Ion pairing in transition metal catalyzed olefin polymerization

Advances in Organometallic Chemistry

Volumn 73, Issue , 2020, Pages 1-78

  Zaccaria, Francesco ^a   Sian, Leonardo ^a,b   Zuccaccia, Cristiano ^a,b   Macchioni, Alceo ^a,b  

^a UNIVERSITY OF PERUGIA   (Italy)

^b DUTCH POLYMER INSTITUTE DPI   (Netherlands)

Author keywords

Catalyst activation; Diffusion; Ion pairs; Methylaluminoxane; NMR; NOE NMR; Olefin polymerization catalysis; Perfluoroborates; Self aggregation; Transition metals; Weakly coordinating anions

Indexed keywords

EID: 85071969218     PISSN: 00653055     EISSN: None     Source Type: Book Series    
DOI: 10.1016/bs.adomc.2019.08.001     Document Type: Chapter

References (468)

1. Macchioni, A., Ion pairing in transition-metal organometallic chemistry. Chem Rev 105 (2005), 2039–2074.
2. Schwaab, G., Sebastiani, F., Havenith, M., Ion hydration and ion pairing as probed by THz spectroscopy. Angew Chem Int Ed 58 (2019), 3000–3013.
3. Chen, E.Y.X., Lancaster, S.J., Weakly coordinating anions: Highly fluorinated borates. Reedijk, J., Poeppelmeier, K., (eds.) Comprehensive Inorganic Chemistry II, 2013, Elsevier, Amsterdam, NL, 707–754.
4. Piers, W.E., The chemistry of perfluoroaryl boranes. Adv Organomet Chem 52 (2004), 1–76.
5. Riddlestone, I.M., Kraft, A., Schaefer, J., Krossing, I., Taming the cationic beast: novel developments in the synthesis and application of weakly coordinating anions. Angew Chem Int Ed 57 (2018), 13982–14024.
6. Merten, C., Pollok, C.H., Liao, S., List, B., Stereochemical communication within a chiral ion pair catalyst. Angew Chem Int Ed 54 (2015), 8841–8845.
7. Khan, M.N., Fagge, I.I., Kinetics and mechanism of cationic micelle/flexible nanoparticle catalysis: a review. Prog React Kinet Mech 43 (2018), 1–20.
8. Teator, A.J., Leibfarth, F.A., Catalyst-controlled stereoselective cationic polymerization of vinyl ethers. Science 363 (2019), 1439–1443.
9. Marcus, Y., Hefter, G., Ion pairing. Chem Rev 106 (2006), 4585–4621.
10. Macchioni, A., Bellachioma, G., Cardaci, G., et al. Counterion effect on CO/styrene copolymerization catalyzed by cationic palladium(II) organometallic complexes: an interionic structural and dynamic investigation based on NMR spectroscopy. Organometallics 18 (1999), 3061–3069.
11. Binotti, B., Carfagna, C., Zuccaccia, C., Macchioni, A., From atactic to isotactic CO/p-methylstyrene copolymer by proper modification of Pd(II) catalysts bearing achiral alpha-diimines. Chem Commun 2 (2005), 92–94.
12. Binotti, B., Bellachioma, G., Cardaci, G., Carfagna, C., Zuccaccia, C., Macchioni, A., The effect of counterion/ligand interplay on the activity and stereoselectivity of palladium(II)-diimine catalysts for CO/p-methylstyrene copolymerization. Chem A Eur J 13 (2007), 1570–1582.
13. Rocchigiani, L., Jia, M., Bandini, M., Macchioni, A., Assessing the Role of Counterion in Gold-Catalyzed Dearomatization of Indoles with Allenamides by NMR Studies. ACS Catal 5 (2015), 3911–3915.
14. Chiappe, C., Mennucci, B., Silvio Pomelli, C., Sanzone, A., Marra, A., A theoretical study of the copper(I)-catalyzed 1,3-dipolar cycloaddition reaction in dabco-based ionic liquids: the anion effect on regioselectivity. Phys Chem Chem Phys 12 (2010), 1958–1962.
15. Lacour, J., Moraleda, D., Chiral anion-mediated asymmetric ion pairing chemistry. Chem Commun, 2009, 7073–7089.
16. Zuccaccia, D., Belpassi, L., Macchioni, A., Tarantelli, F., Ligand effects on bonding and ion pairing in cationic gold(I) catalysts bearing unsaturated hydrocarbons. Eur J Inorg Chem, 2013, 4121–4135.
17. Jia, M., Bandini, M., Counterion Effects in Homogeneous Gold Catalysis. ACS Catal 5 (2015), 1638–1652.
18. Zuccaccia, D., Belanzoni, P., Belpassi, L., Ciancaleoni, G., Del Zotto, A., Role of ion pairing in the mechanisms of Au(i)-catalysed Reactions: theory and experiment. Mahmudov, K.T., Kopylovich, M.N.M., Silva, F.C.G., Pombeiro, A.J.L., (eds.) Noncovalent Interactions in Catalysis, 2019, The Royal Society of Chemistry, London, UK, 564–578.
19. Bochmann, M., Kinetic and mechanistic aspects of metallocene polymerisation catalysts. J Organomet Chem 689 (2004), 3982–3998.
20. Chen, E.Y.-X., Marks, T.J., Cocatalysts for metal-catalyzed olefin polymerization: activators, activation processes, and structure − activity relationships. Chem Rev 100 (2000), 1391–1434.
21. Bochmann, M., The chemistry of catalyst activation: the case of group 4 polymerization catalysts. Organometallics 29 (2010), 4711–4740.
22. Kempe, R., The co-catalyst is the key. Nat Catal 2 (2019), 184–185.
23. Hooper, M.S., Michalak, A., Computational modeling of polymerization catalysts. Handbook of Transition Metal Polymerization Catalysts, 2018, Wiley-VCH, Weinheim, Germany, 67–110.
24. Fuoss, R.M., Kraus, C.A., Properties of electrolytic solutions. III. The dissociation constant. J Am Chem Soc 55 (1933), 1019–1028.
25. Endeward, B., Brant, P., Nielsen, R.D., Bernardo, M., Zick, K., Thomann, H., Aggregation of borate salts in hydrocarbon solvents. J Phys Chem C 112 (2008), 7818–7828.
26. Rocchigiani, L., Bellachioma, G., Ciancaleoni, G., et al. Anion-dependent tendency of di-long-chain quaternary ammonium salts to form ion quadruples and higher aggregates in benzene. ChemPhysChem 11 (2010), 3243–3254.
27. - anions from zirconocene methyl cations by neutral ligand molecules: equilibria, kinetics, and mechanisms. Organometallics 21 (2002), 473–483.
28. - and an evaluation of activated versions for the polymerization of 1-hexene. Organometallics 18 (1999), 3649–3670.
29. 3. Organometallics 13 (1994), 2235–2243.
30. Stephan, D.W., Stewart, J.C., Guérin, F., Spence, R.E.v.H., Xu, W., Harrison, D.G., Phosphinimides as a steric equivalent to cyclopentadienyl: an approach to ethylene polymerization catalyst design. Organometallics 18 (1999), 1116–1118.
31. 2H-labeling scheme for active-site counts in metallocene-catalyzed alkene polymerization. J Am Chem Soc 123 (2001), 2915–2916.
32. Metz, M.V., Schwartz, D.J., Stern, C.L., Marks, T.J., Nickias, P.N., New perfluoroarylborane activators for single-site olefin polymerization. Acidity and cocatalytic properties of a “superacidic” perfluorodiboraanthracene. Organometallics 21 (2002), 4159–4168.
33. Theurkauff, G., Bader, M., Marquet, N., et al. Discrete ionic complexes of highly isoselective zirconocenes. Solution dynamics, trimethylaluminum adducts, and implications in propylene polymerization. Organometallics 35 (2016), 258–276.
34. Chen, Y.-X., Stern, C.L., Marks, T.J., Very large counteranion modulation of cationic metallocene polymerization activity and stereoregulation by a sterically congested (perfluoroaryl)fluoroaluminate. J Am Chem Soc 119 (1997), 2582–2583.
35. 1H-NOESY NMR spectroscopy to the investigation of ion pair solution structures of organometallic complexes by the detection of interionic contacts. Organometallics 15 (1996), 4349–4351.
36. Macchioni, A., Elucidation of the solution structures of transition metal complex ion pairs by NOE NMR experiments. Eur J Inorg Chem 2003 (2003), 195–205.
37. 19F heteronuclear overhauser spectroscopy (HOESY) NMR methods in inorganic and organometallic chemistry: something old and something new. Chem Rev 105 (2005), 2977–2998.
38. Macchioni, A., Ciancaleoni, G., Zuccaccia, C., Zuccaccia, D., Determining accurate molecular sizes in solution through NMR diffusion spectroscopy. Chem Soc Rev 37 (2008), 479–489.
39. Brintzinger, H.H., Fischer, D., Mülhaupt, R., Rieger, B., Waymouth, R.M., Stereospecific olefin polymerization with chiral metallocene catalysts. Angew Chem Int Ed Engl 34 (1995), 1143–1170.
40. Bochmann, M., Cationic group 4 metallocene complexes and their role in polymerisation catalysis: the chemistry of well defined Ziegler catalysts. J Chem Soc Dalton Trans, 1996, 255–270.
41. Ziegler, K., Holzkamp, E., Breil, H., Martin, H., Polymerisation von Äthylen und anderen Olefinen. Angew Chem, 67, 1955, 426.
42. Natta, G., Pino, P., Corradini, P., et al. Crystalline high polymers of α-olefins. J Am Chem Soc 77 (1955), 1708–1710.
43. Wilkinson, G., Birmingham, J.M., Bis-cyclopentadienyl compounds of Ti, Zr, V, Nb and Ta. J Am Chem Soc 76 (1954), 4281–4284.
44. Natta, G., Pino, P., Mazzanti, G., Giannini, U., A crystallizable organometallic complex containing titanium and aluminum. J Am Chem Soc 79 (1957), 2975–2976.
45. Breslow, D.S., Newburg, N.R., Bis-(cyclopentadienyl)-titanium dichloride —alkylaluminum complexls as catalysts for the polymerization of ethylene. J Am Chem Soc 79 (1957), 5072–5073.
46. Waters, J.A., Mortimer, G.A., Titanium reduction in a soluble Ziegler—Natta catalyst. J Organomet Chem 77 (1974), 231–240.
47. Henrici-olivé, G., Olivé, S., The active species in homogeneous Ziegler-Natta catalysts for the polymerization of ethylene. Angew Chem Int Ed Engl 6 (1967), 790–798.
48. Cossee, P., Ziegler-Natta catalysis I. Mechanism of polymerization of α-olefins with Ziegler-Natta catalysts. J Catal 3 (1964), 80–88.
49. Natta, G., Pino, P., Mazzanti, G., Giannini, U., Mantica, E., Peraldo, M., The nature of some soluble catalysts for low pressure ethylene polymerization. J Polym Sci 26 (1957), 120–123.
50. Long, W.P., Breslow, D.S., Polymerization of ethylene with bis-(cyclopentadienyl)-titanium dichloride and diethylaluminum chloride. J Am Chem Soc 82 (1960), 1953–1957.
51. Breslow, D.S., Newburg, N.R., Bis-(cyclopentadienyl)-titanium dichloride-alkylaluminum complexes as soluble catalysts for the polymerization of ethylene. J Am Chem Soc 81 (1959), 81–86.
52. 2/ethylen. Die Makromol Chem 182 (1981), 3265–3278.
53. Long, W.P., Complexes of aluminum chloride and methylaluminum dichloride with bis-(cyclopentadienyl)-titanium dichloride as catalysts for the polymerization of ethylene. J Am Chem Soc 81 (1959), 5312–5316.
54. Chien, J.C.W., Kinetics of ethylene polymerization catalyzed by bis-(cyclopentadienyl)-titanium dichloride-dimethylaluminum chloride. J Am Chem Soc 81 (1959), 86–92.
55. Schubert, K.H., Reichert, E., Kinetik der äthylenpolymerisation mit löslichen Ziegler-Nnatta-katalysatoren. Die Makromol Chem 123 (1969), 58–72.
56. Natta, G., Mazzanti, G., Organometallic complexes as catalysts in ionic polymerizations. Tetrahedron 8 (1960), 86–100.
57. Busico, V., Cipullo, R., Chadwick, J.C., Modder, J.F., Sudmeijer, O., Effects of regiochemical and stereochemical errors on the course of isotactic propene polyinsertion promoted by homogeneous Ziegler-Natta catalysts. Macromolecules 27 (1994), 7538–7543.
58. Jüngling, S., Mülhaupt, R., Stehling, U., Brintzinger, H.-H., Fischer, D., Langhauser, F., The role of dormant sites in propene polymerization using methyl activated metallocene catalysts. Macromol Symp 97 (1995), 205–216.
59. 2. J Am Chem Soc 107 (1985), 7219–7221.
60. Desert, X., Carpentier, J.-F., Kirillov, E., Quantification of active sites in single-site group 4 metal olefin polymerization catalysis. Coord Chem Rev 386 (2019), 50–68.
61. Ehm, C., Zaccaria, F., Cipullo, R., From mechanistic investigation to quantitative prediction: kinetics of homogeneous transition metal-catalyzed α-olefin polymerization predicted by computational chemistry. Soroush, M., (eds.) Computational Quantum Chemistry, 2019, Elsevier, Amsterdam, NL, 287–326.
62. Henrici-Olivé, G., Olivé, S., Mechanistic studies with homogeneous Ziegler-Natta catalysts. J Organomet Chem 16 (1969), 339–341.
63. Dyachkovskii, F.S., Shilova, A.K., Shilov, A.E., The role of free ions in reactions of olefins with soluble complex catalysts. J Polym Sci Part C Polym Symp 16 (1967), 2333–2339.
64. 13C-NMR-Spektroskopie. Die Angew Makromol Chem 94 (1981), 25–47.
65. 13C-NMR-Spektroskopie. Die Angew Makromol Chem 96 (1981), 1–20.
66. 13C-NMR spectroscopy. The time-development of chain propagation and oligomer distribution. Die Angew Makromol Chem 154 (1987), 1–21.
67. Eisch, J.J., Pombrik, S.I., Zheng, G.-X., Role of ion-pair equilibria in homogeneous Ziegler-Natta olefin polymerization catalysis. Makromol Chem Macromol Symp 66 (1993), 109–120.
68. 3. Organometallics 10 (1991), 3417–3419.
69. Eisch, J.J., Manfre, R.J., Komar, D.A., Regiospecific and stereoselective carbometallation of alkynylsilanes by Ziegler-Natta alkylating agents. J Organomet Chem 159 (1978), C13–C19.
70. Eisch, J.J., Caldwell, K.R., Active sites in soluble ziegler polymerization catalysts generated from titanocene halides and organoaluminum lewis acids. Moser, W.R., Slocum, D.W., (eds.) Homogeneous Transition Metal Catalyzed Reactions, vol 230, 1992, American Chemical Society, Washington, DC, 575–590.
71. Watson, P.L., Parshall, G.W., Organolanthanides in catalysis. Acc Chem Res 18 (1985), 51–56.
72. Jeske, G., Lauke, H., Mauermann, H., Swepston, P.N., Schumann, H., Marks, T.J., Highly reactive organolanthanides. Systematic routes to and olefin chemistry of early and late bis(pentamethylcyclopentadienyl) 4f hydrocarbyl and hydride complexes. J Am Chem Soc 107 (1985), 8091–8103.
73. Watson, P.L., Ziegler-Natta polymerization: the lanthanide model. J Am Chem Soc 104 (1982), 337–339.
74. Watson, P.L., Facile C–H activation by lutetium–methyl and lutetium–hydride complexes. J Chem Soc Chem Commun, 1983, 276–277.
75. Zijlstra, H.S., Harder, S., Methylalumoxane—history, production, properties, and applications. Eur J Inorg Chem 2015 (2015), 19–43.
76. Sinn, H., Kaminsky, W., Ziegler-Natta catalysis. Adv Organomet Chem 18 (1980), 99–149.
77. Sinn, H., Kaminsky, W., Vollmer, H.-J., Woldt, R., Verfahren zur herstellung von polymeren und copolymeren des ethylens. PCT Int Appl DE, 3007725, 1980.
78. Sinn, H., Kaminsky, W., Vollmer, H.-J., Woldt, R., “Living polymers” on polymerization with extremely productive Ziegler Catalysts. Angew Chem Int Ed Engl 19 (1980), 390–392.
79. Long, W.P., Breslow, D.S., Der Einfluß von Wasser auf die katalytische Aktivität von Bis(-cyclopentadienyl)titandichlorid-Dimethylaluminiumchlorid zur Polymerisation von Äthylen. Justus Liebigs Ann Chem 1975 (1975), 463–469.
80. Reichert, K.H., Meyer, K.R., Zur kinetik der niederdruckpolymerisation von äthylen mit löslichen ZIEGLER-katalysatoren. Die Makromol Chem 169 (1973), 163–176.
81. Kaminsky, W., The discovery of metallocene catalysts and their present state of the art. J Polym Sci Part A Polym Chem 42 (2004), 3911–3921.
82. Kaminsky, W., Discovery of methylaluminoxane as cocatalyst for olefin polymerization. Macromolecules 45 (2012), 3289–3297.
83. Laine, A., Linnolahti, M., Pakkanen, T.A., Alkylation and activation of metallocene polymerization catalysts by reactions with trimethylaluminum: a computational study. J Organomet Chem 716 (2012), 79–85.
84. Eilertsen, J.L., Støvneng, J.A., Ystenes, M., Rytter, E., Activation of metallocenes for olefin polymerization as monitored by IR spectroscopy. Inorg Chem 44 (2005), 4843–4851.
85. Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Selectivity in propene polymerization with metallocene catalysts. Chem Rev 100 (2000), 1253–1346.
86. Busico, V., Cipullo, R., Microstructure of polypropylene. Prog Polym Sci 26 (2001), 443–533.
87. Coates, G.W., Precise control of polyolefin stereochemistry using single-site metal catalysts. Chem Rev 100 (2000), 1223–1252.
88. Corradini, P., Guerra, G., Cavallo, L., Do new century catalysts unravel the mechanism of stereocontrol of old Ziegler − Natta catalysts?. Acc Chem Res 37 (2004), 231–241.
89. Tullo, A.H., Metallocene raise again. Chem Eng News 88 (2010), 10–16.
90. McKnight, A.L., Waymouth, R.M., Group 4 ansa-cyclopentadienyl-amido catalysts for olefin polymerization. Chem Rev 98 (1998), 2587–2598.
91. Britovsek, G.J.P., Gibson, V.C., Wass, D.F., The search for new-generation olefin polymerization catalysts: life beyond metallocenes. Angew Chem Int Ed 38 (1999), 428–447.
92. Baier, M.C., Zuideveld, M.A., Mecking, S., Post-metallocenes in the industrial production of polyolefins. Angew Chem Int Ed 53 (2014), 9722–9744.
93. Klosin, J., Fontaine, P.P., Figueroa, R., Development of group IV molecular catalysts for high temperature ethylene-α-olefin copolymerization reactions. Acc Chem Res 48 (2015), 2004–2016.
94. Sauter, D., Taoufik, M., Boisson, C., Polyolefins, a success story. Polymers, 9, 2017, 185.
95. Busico, V., Metal-catalysed olefin polymerisation into the new millennium: a perspective outlook. Dalton Trans 41 (2009), 8794–8802.
96. Stürzel, M., Mihan, S., Mülhaupt, R., From multisite polymerization catalysis to sustainable materials and all-polyolefin composites. Chem Rev 116 (2016), 1398–1433.
97. Severn, J.R., Chadwick, J.C., Immobilisation of homogeneous olefin polymerisation catalysts. Factors influencing activity and stability. Dalton Trans 42 (2013), 8979–8987.
98. Severn, J.R., Chadwick, J.C., Duchateau, R., Friederichs, N., “Bound but not gagged”immobilizing single-site α-olefin polymerization catalysts. Chem Rev 105 (2005), 4073–4147.
99. Bashir, M.A., Monteil, V., Boisson, C., McKenna, T.F.L., The effect of aluminum alkyls and BHT-H on reaction kinetics of silica supported metallocenes and polymer properties in slurry phase ethylene polymerization. J Appl Polym Sci, 135, 2018, 45670.
100. Piers, W.E., Chivers, T., Pentafluorophenylboranes: from obscurity to applications. Chem Soc Rev 26 (1997), 345–354.
101. Shoken, D., Sharma, M., Botoshansky, M., Tamm, M., Eisen, M.S., Mono(imidazolin-2-iminato) titanium complexes for ethylene polymerization at low amounts of methylaluminoxane. J Am Chem Soc 135 (2013), 12592–12595.
102. Sun, Y., Xu, B., Shiono, T., Cai, Z., Highly active ansa-(Fluorenyl)(amido)titanium-based catalysts with low load of methylaluminoxane for syndiotactic-specific living polymerization of propylene. Organometallics 36 (2017), 3009–3012.
103. Kleinschmidt, R., van der Leek, Y., Reffke, M., Fink, G., Kinetics and mechanistic insight into propylene polymerization with different metallocenes and various aluminium alkyls as cocatalysts. J Mol Catal A Chem 148 (1999), 29–41.
104. Jüngling, S., Mülhaupt, R., The influence of methylalumoxane concentration on propene polymerization with homogeneous metallocene-based Ziegler-Natta catalysts. J Organomet Chem 497 (1995), 27–32.
105. Kaminsky, W., How to reduce the ratio mao/metallocene. Macromol Symp 97 (1995), 79–89.
106. Zurek, E., Ziegler, T., Theoretical studies of the structure and function of MAO (methylaluminoxane). Prog Polym Sci 29 (2004), 107–148.
107. Pasynkiewicz, S., Alumoxanes: synthesis, structures, complexes and reactions. Polyhedron 9 (1990), 429–453.
108. Reddy, S.S., Sivaram, S., Homogeneous metallocene-methylaluminoxane catalyst systems for ethylene polymerization. Prog Polym Sci 20 (1995), 309–367.
109. Pédeutour, J.-N., Radhakrishnan, K., Cramail, H., Deffieux, A., Reactivity of metallocene catalysts for olefin polymerization: influence of activator nature and structure. Macromol Rapid Commun 22 (2001), 1095–1123.
110. m nanotubes in methylaluminoxane (MAO): a first-principles investigation. Macromolecules 47 (2014), 8556–8569.
111. n in methylaluminoxane (MAO). A theoretical study based on a combined quantum mechanical and statistical mechanical approach. Inorg Chem 40 (2001), 361–370.
112. Siedle, A.R., Newmark, R.A., Lamanna, W.M., Schroepfer, J.N., Exchange reactions between dialkylzirconocene and alkylaluminium compounds. Polyhedron 9 (1990), 301–308.
113. 2TiMeCl/methylalumoxane systems, catalysts for olefin polymerization. Macromol Rapid Commun 15 (1994), 217–223.
114. 13C NMR spectroscopy. Macromol Symp 89 (1995), 289–298.
115. Tritto, I., Méalares, C., Sacchi, M.C., Locatelli, P., Methylaluminoxane: NMR analysis, cryoscopic measurements and cocatalytic ability in ethylene polymerization. Macromol Chem Phys 198 (1997), 3963–3977.
116. Babushkin, D.E., Brintzinger, H.-H., Activation of dimethyl zirconocene by methylaluminoxane (MAO)size estimate for Me-MAO- anions by pulsed field-gradient NMR. J Am Chem Soc 124 (2002), 12869–12873.
117. Ghiotto, F., Pateraki, C., Tanskanen, J., et al. Probing the structure of methylalumoxane (MAO) by a combined chemical, spectroscopic, neutron scattering, and computational approach. Organometallics 32 (2013), 3354–3362.
118. Trefz, T.K., Henderson, M.A., Wang, M.Y., Collins, S., McIndoe, J.S., Mass Spectrometric characterization of methylaluminoxane. Organometallics 32 (2013), 3149–3152.
119. Linnolahti, M., Severn, J.R., Pakkanen, T.A., Formation of nanotubular methylaluminoxanes and the nature of the active species in single-site α-olefin polymerization catalysis. Angew Chem 120 (2008), 9419–9423.
120. Linnolahti, M., Collins, S., Formation, structure, and composition of methylaluminoxane. ChemPhysChem 18 (2017), 3369–3374.
121. Zijlstra, H.S., Stuart, M.C.A., Harder, S., Structural investigation of methylalumoxane using transmission electron microscopy. Macromolecules 48 (2015), 5116–5119.
122. Zijlstra, H., Collins, S., McIndoe, J.S., Oxidation of methylalumoxane oligomers. Chem A Eur J 24 (2018), 5506–5512.
123. Endres, E., Zijlstra, H.S., Collins, S., McIndoe, J.S., Linnolahti, M., Oxidation of methylalumoxane oligomers: a theoretical study guided by mass spectrometry. Organometallics 37 (2018), 3936–3942.
124. Zijlstra, H.S., Linnolahti, M., Collins, S., McIndoe, J.S., Additive and aging effects on methylalumoxane oligomers. Organometallics 36 (2017), 1803–1809.
125. Imhoff, D.W., Simeral, L.S., Sangokoya, S.A., Peel, J.H., Characterization of methylaluminoxanes and determination of trimethylaluminum using proton NMR. Organometallics 17 (1998), 1941–1945.
126. Jordan, D.E., Visual titrimetric determination of total reactivity and differentiation of trialkylaluminum and dialkylaluminum hydride in mixtures. Anal Chem 40 (1968), 2150–2153.
127. Resconi, L., Bossi, S., Abis, L., Study on the role of methylalumoxane in homogeneous olefin polymerization. Macromolecules 23 (1990), 4489–4491.
128. Barron, A.R., New method for the determination of the trialkylaluminum content in alumoxanes. Organometallics 14 (1995), 3581–3583.
129. Von Lacroix, K., Heitmann, B., Sinn, H., Behaviour of differently produced methylalumoxanes in the phase separation with diethyl ether and molecular weight estimations. Macromol Symp 97 (1995), 137–142.
130. Ghiotto, F., Pateraki, C., Severn, J.R., Friederichs, N., Bochmann, M., Rapid evaluation of catalysts and MAO activators by kinetics: what controls polymer molecular weight and activity in metallocene/MAO catalysts?. Dalton Trans 42 (2013), 9040–9048.
131. Cam, D., Giannini, U., Concerning the reaction of zirconocene dichloride and methylalumoxane: homogeneous Ziegler-Natta catalytic system for olefin polymerization. Die Makromol Chem 193 (1992), 1049–1055.
132. 13C NMR spectra of organoaluminum compounds: evidence for an oxygen-aluminum π-interaction. J Organomet Chem 179 (1979), 1–6.
133. n. J Am Chem Soc 115 (1993), 4971–4984.
134. 6: determination of the steric limitation of a latent lewis acid. Organometallics 15 (1996), 5514–5518.
135. 27Al NMR with comparison to EFG tensors from ab initio molecular orbital calculations. J Am Chem Soc 123 (2001), 12009–12017.
136. - anion. Organometallics 2 (1983), 985–989.
137. 27Al solid-state NMR spectrum of methylaluminoxane (MAO) at variable temperatures and field strengths. Phys Chem Chem Phys 18 (2016), 24106–24118.
138. 27AI-NMR spectroscopy: a probe for three-, four-, five-, and sixfold coordinated Al atoms in organoaluminum compounds. Angew Chem Int Ed Engl 22 (1983), 779–780.
139. Nekhaeva, L.A., Bondarenko, G.N., Rykov, S.V., et al. IR and NMR studies on zirconocene dichloride/methylalumoxane systems-catalysts for olefin polymerization. J Organomet Chem 406 (1991), 139–146.
140. 27Al-NMR spectra. J Mol Catal 82 (1993), 93–101.
141. Babushkin, D.E., Semikolenova, N.V., Panchenko, V.N., Sobolev, A.P., Zakharov, V.A., Talsi, E.P., Multinuclear NMR investigation of methylaluminoxane. Macromol Chem Phys 198 (1997), 3845–3854.
142. Zakharov, V.A., Talzi, E.P., Zakharov, I.I., Babushkin, D.E., Semikolenova, N.V., Structure of methylaluminoxane and the mechanism of active center formation in the zirconocene/methylaluminoxane catalytic system. Kinet Catal 40 (1999), 836–850.
143. Giannetti, E., Nicoletti, G.M., Mazzocchi, R., Homogeneous Ziegler–Natta catalysis. II. Ethylene polymerization by IVB transition metal complexes/methyl aluminoxane catalyst systems. J Polym Sci Polym Chem Ed 23 (1985), 2117–2134.
144. Ystenes, M., Eilertsen, J.L., Liu, J., Ott, M., Rytter, E., Støvneng, J.A., Experimental and theoretical investigations of the structure of methylaluminoxane (MAO) cocatalysts for olefin polymerization. J Polym Sci Part A Polym Chem 38 (2000), 3106–3127.
145. Rytter, E., Støvneng, J.A., Eilertsen, J.L., Ystenes, M., Reactivity and acidity of alkylaluminoxanes. Organometallics 20 (2001), 4466–4468.
146. Trefz, T.K., Henderson, M.A., Linnolahti, M., Collins, S., McIndoe, J.S., Mass spectrometric characterization of methylaluminoxane-activated metallocene complexes. Chem A Eur J 21 (2015), 2980–2991.
147. Henderson, M.A., Trefz, T.K., Collins, S., Wang, M.Y., McIndoe, J.S., Characterization of isobutylaluminoxanes by electrospray ionization mass spectrometry. Organometallics 32 (2013), 2079–2083.
148. Talsi, E.P., Semikolenova, N.V., Panchenko, V.N., et al. The metallocene/methylaluminoxane catalysts formation: EPR spin probe study of Lewis acidic sites of methylaluminoxane. J Mol Catal A Chem 139 (1999), 131–137.
149. 1H NMR, and polymerization study. Macromol Chem Phys 207 (2006), 327–335.
150. Talsi, E.P., Bryliakov, K.P., NMR and EPR spectroscopy in the study of the mechanisms of metallocene and post-metallocene polymerization and oligomerization of α-olefins. Talsi, E.P., Bryliakov, K.P., (eds.) Applications of EPR and NMR Spectroscopy in Homogeneous Catalysis, 2017, CRC Press, Boca Raton, FL, 127–218.
151. 2F: mimicking cation–anion interactions in metallocenium–methylalumoxane inner-sphere ion pairs. Angew Chem Int Ed 56 (2017), 14227–14231.
152. n found in methylaluminoxane (MAO) solution. Inorg Chem 40 (2001), 3279–3292.
153. Zurek, E., Ziegler, T., Toward the identification of dormant and active species in MAO (Methylaluminoxane)-activated, dimethylzirconocene-catalyzed olefin polymerization. Organometallics 21 (2002), 83–92.
154. Linnolahti, M., Laine, A., Pakkanen, T.A., Screening the thermodynamics of trimethylaluminum-hydrolysis products and their Co-catalytic performance in olefin-polymerization catalysis. Chem A Eur J 19 (2013), 7133–7142.
155. n oligomers in methylaluminoxane solution: the identification of a geometry-based descriptor. Organometallics 31 (2012), 8312–8322.
156. Linnolahti, M., Luhtanen, T.N.P., Pakkanen, T.A., Theoretical studies of aluminoxane chains, rings, cages, and nanostructures. Chem A Eur J 10 (2004), 5977–5987.
157. Linnolahti, M., Severn, J.R., Pakkanen, T.A., Are aluminoxanes nanotubular? Structural evidence from a quantum chemical study. Angew Chem Int Ed 45 (2006), 3331–3334.
158. Hirvi, J.T., Bochmann, M., Severn, J.R., Linnolahti, M., Formation of octameric methylaluminoxanes by hydrolysis of trimethylaluminum and the mechanisms of catalyst activation in single-site α-olefin polymerization catalysis. ChemPhysChem 15 (2014), 2732–2742.
159. Rocchigiani, L., Busico, V., Pastore, A., Macchioni, A., Probing the interactions between all components of the catalytic pool for homogeneous olefin polymerisation by diffusion NMR spectroscopy. Dalton Trans 42 (2013), 9104–9111.
160. 1H NMR spin-lattice relaxation time. Macromol Chem Phys 202 (2001), 2880–2889.
161. Zaccaria, F., Zuccaccia, C., Cipullo, R., et al. BHT-modified MAO: cage size estimation, chemical counting of strongly acidic al sites, and activation of a Ti-phosphinimide precatalyst. ACS Catal 9 (2019), 2996–3010.
162. Zaccaria, F., Zuccaccia, C., Cipullo, R., Macchioni, A., Extraction of reliable molecular information from diffusion NMR spectroscopy: hydrodynamic volume or molecular mass?. Chem A Eur J 25 (2019), 9930–9937, 10.1002/chem.201900812.
163. Zijlstra, H.S., Joshi, A., Linnolahti, M., Collins, S., McIndoe, J.S., Modifying methylalumoxane via alkyl exchange. Dalton Trans 47 (2018), 17291–17298.
164. Kaminsky, W., Bark, A., Steiger, R., Stereospecific polymerization by metallocene/aluminoxane catalysts. J Mol Catal 74 (1992), 109–119.
165. Kaminsky, W., Strübel, C., Hydrogen transfer reactions of supported metallocene catalysts. J Mol Catal A Chem 128 (1998), 191–200.
166. Pédeutour, J.-N., Radhakrishnan, K., Cramail, H., Deffieux, A., Use of “TMA-depleted” MAO for the activation of zirconocenes in olefin polymerization. J Mol Catal A Chem 185 (2002), 119–125.
167. Busico, V., Cipullo, R., Cutillo, F., Friederichs, N., Ronca, S., Wang, B., Improving the performance of methylalumoxane: a facile and efficient method to trap “Free” trimethylaluminum. J Am Chem Soc 125 (2003), 12402–12403.
168. Galimberti, M., Destro, M., Fusco, O., Piemontesi, F., Camurati, I., Ethene/propene copolymerization from metallocene-based catalytic systems: role of the alumoxane. Macromolecules 32 (1999), 258–263.
169. Smith, G.M., Palmaka, S.W., Roger, J.S., Malpass, D.B., Monfiston, D.J., Polyalkylaluminoxane Compositions Formed by Non-Hydrolytic Means. PCT Int. Appl. WO9723288, 1997.
170. 2/MAO olefin polymerization catalytic system, 1. Investigation in toluene. Macromol Chem Phys 199 (1998), 1451–1457.
171. Beck, S., Brintzinger, H.H., Alkyl exchange between aluminum trialkyls and zirconocene dichloride complexes—a measure of electron densities at the Zr center. Inorg Chim Acta 270 (1998), 376–381.
172. Pédeutour, J.-N., Cramail, H., Deffieux, A., The negative role of chloride counter-anion in the activation process of zirconocene dichloride by methylaluminoxane. J Mol Catal A Chem 174 (2001), 81–87.
173. Kuklin, M.S., Hirvi, J.T., Bochmann, M., Linnolahti, M., Toward controlling the metallocene/methylaluminoxane-catalyzed olefin polymerization process by a computational approach. Organometallics 34 (2015), 3586–3597.
174. 13C NMR study of the reaction equilibria and polymerization. Macromol Symp 97 (1995), 101–108.
175. Pédeutour, J.-N., Radhakrishnan, K., Cramail, H., Deffieux, A., Elementary mechanisms of metallocene activation by methylaluminoxane cocatalysts for olefin polymerization. Polym Int 51 (2002), 973–977.
176. Harlan, C.J., Bott, S.G., Barron, A.R., Three-coordinate aluminum is not a prerequisite for catalytic activity in the zirconocene-alumoxane polymerization of ethylene. J Am Chem Soc 117 (1995), 6465–6474.
177. 2-catalyzed ethylene polymerization: further evidence for the structural assignment of active and dormant species. Faraday Discuss 124 (2003), 93–109.
178. Zijlstra, H., Joshi, A., Linnolahti, M., Collins, S., JS, M.I., Interaction of neutral donors with methylaluminoxane. Eur J Inorg Chem 2019 (2019), 2346–2355, 10.1002/ejc.201900153.
179. Sishta, C., Hathorn, R.M., Marks, T.J., Group 4 metallocene-alumoxane olefin polymerization catalysts. CPMAS-NMR spectroscopic observation of cation-like zirconocene alkyls. J Am Chem Soc 114 (1992), 1112–1114.
180. 2 (X = Me, Cl) by methylaluminoxane as studied by electrospray ionization mass spectrometry: relationship to polymerization catalysis. Macromolecules 50 (2017), 8871–8884.
181. 2. J Organomet Chem 572 (1999), 169–175.
182. Talsi, E.P., Bryliakov, K.P., Semikolenova, N.V., Zakharov, V.A., Bochmann, M., Key intermediates in metallocene-and post-metallocene-catalyzed polymerization. Kinet Catal 48 (2007), 490–504.
183. 4]-activated systems. Organometallics 27 (2008), 6333–6342.
184. Babushkin, D.E., Semikolenova, N.V., Zakharov, V.A., Talsi, E.P., Mechanism of dimethylzirconocene activation with methylaluminoxane: NMR monitoring of intermediates at high Al/Zr ratios. Macromol Chem Phys 201 (2000), 558–567.
185. 2 with methylaluminoxane (MAO). Organometallics 23 (2004), 149–152.
186. 13C-NMR and ethylene polymerization studies of zirconocene/MAO catalysts: effect of the ligand structure on the formation of active intermediates and polymerization kinetics. J Organomet Chem 683 (2003), 92–102.
187. Bryliakov, K.P., Kravtsov, E.A., Pennington, D.A., et al. Active intermediates in ethylene polymerization over titanium bis(phenoxyimine) catalysts. Organometallics 24 (2005), 5660–5664.
188. -. Organometallics 26 (2007), 1536–1540.
189. 13C NMR study of the reaction equilibria and polymerization. Macromolecules 28 (1995), 5358–5362.
190. Tritto, I., Donetti, R., Sacchi, M.C., Locatelli, P., Zannoni, G., Dimethylzirconocene − methylaluminoxane catalyst for olefin polymerization: NMR study of reaction equilibria. Macromolecules 30 (1997), 1247–1252.
191. 2-based catalysts. Macromolecules 32 (1999), 264–269.
192. 13C-NMR study. Dalton Trans, 2006, 4539–4544.
193. 19F NMR spectroscopic probe. Organometallics 22 (2003), 3558–3565.
194. 2 by methylaluminoxane. J Mol Catal A Chem 176 (2001), 87–94.
195. 2 by methylaluminoxane, 4. UV/visible spectroscopic study in hydrocarbon and chlorinated media. Macromol Chem Phys 200 (1999), 1215–1221.
196. Wieser, U., Schaper, F., Brintzinger, H.-H., Methylalumoxane (MAO)-derived MeMAO − anions in zirconocene-based polymerization catalyst systems—A UV-vis spectroscopic study. Macromol Symp 236 (2006), 63–68.
197. Jiang, J., Zhang, H., Li, M., et al. Droplet spray ionization from a glass microscope slide: real-time monitoring of ethylene polymerization. Anal Chem 87 (2015), 8057–8062.
198. Beck, S., Prosenc, M.-H., Brintzinger, H.-H., Goretzki, R., Herfert, N., Fink, G., Binuclear zirconocene cations with μ-CH3-bridges in homogeneous Ziegler-Natta catalyst systems. J Mol Catal A Chem 111 (1996), 67–79.
199. Bochmann, M., Lancaster, S.J., Monomer–dimer equilibria in homo- and heterodinuclear cationic alkylzirconium complexes and their role in polymerization catalysis. Angew Chem Int Ed Engl 33 (1994), 1634–1637.
200. Tymińska, N., Zurek, E., DFT-D investigation of active and dormant methylaluminoxane (MAO) species grafted onto a magnesium dichloride cluster: a model study of supported MAO. ACS Catal 5 (2015), 6989–6998.
201. Xu, Z., Vanka, K., Firman, T., et al. Theoretical study of the interactions between cations and anions in group IV transition-metal catalysts for single-site homogeneous olefin polymerization. Organometallics 21 (2002), 2444–2453.
202. Song, F., Cannon, R.D., Bochmann, M., Zirconocene-catalyzed propene polymerization: a quenched-flow kinetic study. J Am Chem Soc 125 (2003), 7641–7653.
203. Machat, M.R., Jandl, C., Rieger, B., Titanocenes in olefin polymerization: sustainable catalyst system or an extinct species?. Organometallics 36 (2017), 1408–1418.
204. Cipullo, R., Melone, P., Yu, Y., Iannone, D., Busico, V., Olefin polymerisation catalysts: when perfection is not enough. Dalton Trans 44 (2015), 12304–12311.
205. Ehm, C., Cipullo, R., Budzelaar, P.H.M., Busico, V., Role(s) of TMA in polymerization. Dalton Trans 45 (2016), 6847–6855.
206. 3. Angew Chem Int Ed 54 (2015), 6343–6346.
207. Klesing, A., Bettonville, S., The effect of substituents on dimer formation and cation–anion interaction in silicon bridged bisindenyl zirconocene propylene polymerization catalysts. Phys Chem Chem Phys 1 (1999), 2373–2377.
208. 6. Organometallics 30 (2011), 3834–3843.
209. +”. Organometallics 17 (1998), 5908–5912.
210. 4]: NMR investigations of the influence of Al/Zr ratios on alkylation and on formation of the precursor of the active metallocene species. J Mol Catal A Chem 184 (2002), 95–110.
211. 4] (X = Cl, Me). J Organomet Chem 692 (2007), 859–868.
212. 3. Organometallics 25 (2006), 5549–5565.
213. 5 transfer agent. Pure Appl Chem, 75, 2003, 1183.
214. Erker, G., Tris(pentafluorophenyl)borane: a special boron Lewis acid for special reactions. Dalton Trans, 2005, 1883–1890.
215. Massey, A.G., Park, A.J., Perfluorophenyl derivatives of the elements: I. Tris(pentafluorophenyl)boron. J Organomet Chem 2 (1964), 245–250.
216. Yang, X., Stern, C.L., Marks, T.J., Cationic zirconocene olefin polymerization catalysts based on the organo-lewis acid tris(pentafluorophenyl)borane. A synthetic,structural, solution dynamic, and polymerization catalytic study. J Am Chem Soc 116 (1994), 10015–10031.
217. Yang, X., Stern, C.L., Marks, T.J., Cation-like homogeneous olefin polymerization catalysts based upon zirconocene alkyls and tris(pentafluorophenyl)borane. J Am Chem Soc 113 (1991), 3623–3625.
218. Ewen, J.A., Elder, M.J., Metallocene Catalysts With Lewis Acids and Aluminum Alkyls. PCT Int. Appl. EP 0427267, 1991.
219. Strauss, S.H., The search for larger and more weakly coordinating anions. Chem Rev 93 (1993), 927–942.
220. 5 bond. Organometallics 16 (1997), 1810–1812.
221. + (M = Ti, Zr) as a deactivation pathway in olefin polymerization catalysis: a combined density functional theory and molecular mechanics investigation. Organometallics 23 (2004), 3847–3852.
222. +] as deactivation pathways in olefin polymerization catalysis: a combined density functional theory and molecular mechanics investigation. Organometallics 24 (2005), 2076–2085.
223. Phomphrai, K., Fenwick, A.E., Sharma, S., et al. Diverse pathways of activation and deactivation of half-sandwich aryloxide titanium polymerization catalysts. Organometallics 25 (2006), 214–220.
224. 5 transfer agent in zirconium chemistry: borole sandwich and borole-bridged triple-decker complexes. Organometallics 20 (2001), 4080–4091.
225. 3: a case study in constructing DFT-based QSARs to predict unimolecular rate constants. RSC Adv 5 (2015), 48246–48254.
226. Sivaev, I.B., Bregadze, V.I., Lewis acidity of boron compounds. Coord Chem Rev 270-271 (2014), 75–88.
227. Chivers, T., Pentafluorophenylboron halides: 40 years later. J Fluor Chem 115 (2002), 1–8.
228. 19F NMR spectroscopy. Coord Chem Rev 252 (2008), 2292–2313.
229. Chen, Y.-X., Stern, C.L., Yang, S., Marks, T.J., Organo-lewis acids as cocatalysts in cationic metallocene polymerization catalysis. unusual characteristics of sterically encumbered tris(perfluorobiphenyl)borane. J Am Chem Soc 118 (1996), 12451–12452.
230. Li, L., Stern, C.L., Marks, T.J., Bis(Pentafluorophenyl)(2-perfluorobiphenylyl)borane. A new perfluoroarylborane cocatalyst for single-site olefin polymerization. Organometallics 19 (2000), 3332–3337.
231. Li, L., Marks, T.J., New organo-lewis acids. Tris(β-perfluoronaphthyl)borane (PNB) as a highly active cocatalyst for metallocene-mediated Ziegler − Natta α-olefin polymerization. Organometallics 17 (1998), 3996–4003.
232. Chen, Y.-X., Metz, M.V., Li, L., Stern, C.L., Marks, T.J., Sterically encumbered (perfluoroaryl) borane and aluminate cocatalysts for tuning cation − anion ion pair structure and reactivity in metallocene polymerization processes. A synthetic, structural, and polymerization study. J Am Chem Soc 120 (1998), 6287–6305.
233. McAdon, M.A., Nickias, P.N., Marks, T.J., Swartz, D.J., Catalyst Activator. PCT Int Appl WO 9906413, 1999.
234. Li, H., Li, L., Schwartz, D.J., et al. Coordination copolymerization of severely encumbered isoalkenes with ethylene: enhanced enchainment mediated by binuclear catalysts and cocatalysts. J Am Chem Soc 127 (2005), 14756–14768.
235. 4 (X = H, F). J Am Chem Soc 121 (1999), 3244–3245.
236. 2. Angew Chem Int Ed 38 (1999), 3695–3698.
237. Metz, M.V., Schwartz, D.J., Stern, C.L., Nickias, P.N., Marks, T.J., Organo-lewis acid cocatalysts in single-site olefin polymerization—a highly acidic perfluorodiboraanthracene. Angew Chem 112 (2000), 1368–1372.
238. Piers, W.E., Irvine, G.J., Williams, V.C., Highly lewis acidic bifunctional organoboranes. Eur J Inorg Chem, 2000, 2131–2142.
239. Parks, D.J., von H. Spence, R.E., Piers, W.E., Bis(pentafluorophenyl)borane: synthesis, properties, and hydroboration chemistry of a highly electrophilic borane reagent. Angew Chem Int Ed Engl 34 (1995), 809–811.
240. 5-cyclopentadienyl)dimethylzirconium: methane elimination versus methyl–hydride exchange and an example of pentacoordinate carbon. Angew Chem Int Ed Engl 34 (1995), 1230–1233.
241. 5). Organometallics 17 (1998), 2459–2469.
242. 2]. Organometallics 19 (2000), 2040–2042.
243. 2-a new organometallic lewis acid for the generation of group 4 metallocene cation complexes. Chem A Eur J 6 (2000), 258–266.
244. Belgardt, T., Storre, J., Roesky, H.W., Noltemeyer, M., Schmidt, H.-G., Tris(pentafluorophenyl)alane: a novel aluminum organyl. Inorg Chem 34 (1995), 3821–3822.
245. Chen, M.-C., Roberts, J.A.S., Marks, T.J., New mononuclear and polynuclear perfluoroarylmetalate cocatalysts for stereospecific olefin polymerization. Organometallics 23 (2004), 932–935.
246. 3-derived metallocenium ion pairs. structural, thermochemical, and structural dynamic divergences. J Am Chem Soc 127 (2005), 10898–10909.
247. 3 and its use for the modification of methylalumoxane. J Mol Catal A Chem 132 (1998), 231–239.
248. Chen, E.Y.-X., Kruper, W.J., Roof, G., Wilson, D.R., “Double activation” of constrained geometry and ansa-metallocene group 4 metal dialkyls: synthesis, structure, and olefin polymerization study of mono- and dicationic aluminate complexes. J Am Chem Soc 123 (2001), 745–746.
249. Stephan, D.W., Olefin polymerization and deactivation pathways of titanium-phosphinimide catalysts. Macromol Symp 173 (2001), 105–116.
250. Al-Humydi, A., Garrison, J.C., Youngs, W.J., Collins, S., Propene polymerization using ansa-metallocenium ions: excess activator effects on polymerization activity and polymer microstructure. Organometallics 24 (2005), 193–196.
251. 4]: thermodynamics, structure, and bonding. Organometallics 38 (2019), 1445–1458.
252. Chien, J.C.W., Tsai, W.M., Rausch, M.D., Isospecific polymerization of propylene catalyzed by rac-Ethylenebis(indenyl)methylzirconium cation. J Am Chem Soc 113 (1991), 8570–8571.
253. Krossing, I., Raabe, I., Noncoordinating anions—fact or fiction? a survey of likely candidates. Angew Chem Int Ed 43 (2004), 2066–2090.
254. Chen, M.-C., Roberts, J.A.S., Seyam, A.M., et al. Diversity in weakly coordinating anions. Mono- and polynuclear halo(perfluoroaryl)metalates as cocatalysts for stereospecific olefin polymerization: synthesis, structure, and reactivity. Organometallics 25 (2006), 2833–2850.
255. Li, L., Metz, M.V., Li, H., et al. Catalyst/cocatalyst nuclearity effects in single-site polymerization. Enhanced polyethylene branching and α-olefin comonomer enchainment in polymerizations mediated by binuclear catalysts and cocatalysts via a new enchainment pathway. J Am Chem Soc 124 (2002), 12725–12741.
256. LaPointe, R.E., Roof, G.R., Abboud, K.A., Klosin, J., New family of weakly coordinating anions. J Am Chem Soc 122 (2000), 9560–9561.
257. - as a weakly coordinating counteranion during zirconocene-induced catalysis of propylene polymerization. Organometallics 24 (2005), 2889–2897.
258. Jia, L., Yang, X., Stern, C.L., Marks, T.J., Cationic metallocene polymerization catalysts based on tetrakis(pentafluorophenyl)borate and Its derivatives. Probing the limits of anion “noncoordination” via a synthetic, solution dynamic, structural, and catalytic olefin polymerization study. Organometallics 16 (1997), 842–857.
259. Jia, L., Yang, X., Ishihara, A., Marks, T.J., Protected (fluoroaryl)borates as effective counteranions for cationic metallocene polymerization catalysts. Organometallics 14 (1995), 3135–3137.
260. 2–. Chem Commun, 1999, 1533–1534.
261. -: a new, remarkably stable diborate anion for metallocene polymerization catalysts. Organometallics 21 (2002), 451–453.
262. Focante, F., Mercandelli, P., Sironi, A., Resconi, L., Complexes of tris(pentafluorophenyl)boron with nitrogen-containing compounds: Synthesis, reactivity and metallocene activation. Coord Chem Rev 250 (2006), 170–188.
263. Jordan, R.F., Dasher, W.E., Echols, S.F., Reactive cationic dicyclopentadienyl zirconium(IV) complexes. J Am Chem Soc 108 (1986), 1718–1719.
264. Jordan, R.F., LaPointe, R.E., Bajgur, C.S., Echols, S.F., Willett, R., Chemistry of cationic zirconium(IV) benzyl complexes. One-electron oxidation of d0 organometallics. J Am Chem Soc 109 (1987), 4111–4113.
265. Ogawa, K., Kitagawa, T., Ishida, S., Komatsu, K., Synthesis and structure of a new tetrakis(pentafluorophenyl)borate salt of the silver(I) cation with novel trigonal planar tris(benzene) coordination. Organometallics 24 (2005), 4842–4844.
266. 12). Organometallics 12 (1993), 2897–2903.
267. –. Chem Rev 113 (2013), PR179–PR233.
268. Reed, C.A., Carboranes: a new class of weakly coordinating anions for strong electrophiles, oxidants, and superacids. Acc Chem Res 31 (1998), 133–139.
269. Bochmann, M., Wilson, L.M., Synthesis and insertion reactions of cationic alkylbis(cyclopentadienyl)titanium complexes. J Chem Soc Chem Commun, 1986, 1610–1611.
270. 4.MeCN. Organometallics 6 (1987), 2556–2563.
271. Lin, Z., Le Marechal, J.F., Sabat, M., Marks, T.J., Models for organometallic molecule-support complexes. Synthesis and properties of cationic organoactinides. J Am Chem Soc 109 (1987), 4127–4129.
272. Hlatky, G.G., Turner, H.W., Eckman, R.R., Ionic, base-free zirconocene catalysts for ethylene polymerization. J Am Chem Soc 111 (1989), 2728–2729.
273. Yang, X., Stern, C., Marks, T.J., Models for organometallic molecule-support complexes. Very large counterion modulation of cationic actinide alkyl reactivity. Organometallics 10 (1991), 840–842.
274. 2Ph). Organometallics 14 (1995), 371–386.
275. Wilson, P.A., Wright, J.A., Oganesyan, V.S., Lancaster, S.J., Bochmann, M., Structural characterization of a cationic zirconocene dimethylaniline complex and related catalytically relevant species. Organometallics 27 (2008), 6371–6374.
276. Wrobel, O., Schaper, F., Wieser, U., Gregorius, H., Brintzinger, H.H., Siloxyaluminum alkyl cations: syntheses, structures, and reactions related to activation of zirconocene catalysts on silica gel surfaces. Organometallics 22 (2003), 1320–1325.
277. Rocchigiani, L., Zuccaccia, C., Zuccaccia, D., Macchioni, A., Self-aggregation tendency of zirconocenium ion pairs which model polymer-chain-carrying species in aromatic and aliphatic solvents with low polarity. Chem A Eur J 14 (2008), 6589–6592.
278. Rocchigiani, L., Bellachioma, G., Ciancaleoni, G., Macchioni, A., Zuccaccia, D., Zuccaccia, C., Synthesis, characterization, interionic structure, and self-aggregation tendency of zirconaaziridinium salts bearing long alkyl chains. Organometallics 30 (2011), 100–114.
279. Rocchigiani, L., Ciancaleoni, G., Zuccaccia, C., Macchioni, A., Low-temperature kinetic NMR studies on the insertion of a single olefin molecule into a Zr-C bond: assessing the counterion–solvent interplay. Angew Chem Int Ed 50 (2011), 11752–11755.
280. Rocchigiani, L., Bellachioma, G., Zuccaccia, C., Macchioni, A., An NMR study on the reaction of substituted dimethyl zirconocenes with dimethylanilinium borate. J Organomet Chem 714 (2012), 32–40.
281. Rocchigiani, L., Macchioni, A., Zuccaccia, C., NMR studies on the dynamic behavior of zirconaaziridinium ion pairs in solution. Organometallics 31 (2012), 4076–4079.
282. Rocchigiani, L., Ciancaleoni, G., Zuccaccia, C., Macchioni, A., An Integrated NMR and DFT study on the single insertion of α-olefins into the M-C bond of group 4 metallaaziridinium ion pairs. ChemCatChem 5 (2013), 519–528.
283. Rios, I.G., Novarino, E., van der Veer, S., Hessen, B., Bouwkamp, M.W., Amine catalyzed solvent C − H bond activation as deactivation route for cationic decamethylzirconocene olefin polymerization catalysts. J Am Chem Soc 131 (2009), 16658–16659.
284. Novarino, E., Guerrero Rios, I., van der Veer, S., Meetsma, A., Hessen, B., Bouwkamp, M.W., Catalyst deactivation reactions: the role of tertiary amines revisited. Organometallics 30 (2011), 92–99.
285. Hlatky, G.G., Eckman, R.R., Turner, H.W., Metallacarboranes as labile anions for ionic zirconocene olefin polymerization catalysts. Organometallics 11 (1992), 1413–1416.
286. +: a convenient reagent for generation and stabilization of cationic, highly electrophilic organometallic complexes. Organometallics 11 (1992), 3920–3922.
287. -. Organometallics 19 (2000), 1442–1444.
288. 3]Li—formation of a useful neutral brønsted acid for the generation of homogeneous metallocene ziegler catalysts. Eur J Inorg Chem, 2001, 535–538.
289. 3B-N-heterocycle complexes, 2. Macromol Chem Phys 205 (2004), 319–333.
290. Binotti, B., Macchioni, A., Zuccaccia, C., Zuccaccia, D., Application of NOE and PGSE NMR methodologies to investigate non-covalent intimate inorganic adducts in solution. Comments Inorg Chem, 23, 2002.
291. Bellachioma, G., Ciancaleoni, G., Zuccaccia, C., Zuccaccia, D., Macchioni, A., NMR investigation of non-covalent aggregation of coordination compounds ranging from dimers and ion pairs up to nano-aggregates. Coord Chem Rev 252 (2008), 2224–2238.
292. Zuccaccia, C., Stahl, N.G., Macchioni, A., Chen, M.-C., Roberts, J.A., Marks, T.J., NOE and PGSE NMR spectroscopic studies of solution structure and aggregation in metallocenium ion-pairs. J Am Chem Soc 126 (2004), 1448–1464.
293. Zuccaccia, C., Bellachioma, G., Cardaci, G., Macchioni, A., Solution structure investigation of Ru(II) complex ion pairs: quantitative NOE measurements and determination of average interionic distances. J Am Chem Soc 123 (2001), 11020–11028.
294. Zuccaccia, C., Bellachioma, G., Cardaci, G., Macchioni, A., Specificity of interionic contacts and estimation of average interionic distances by NOE NMR measurements in solution of cationic Ru(II) organometallic complexes bearing unsymmetrical counterions. Organometallics 18 (1999), 1–3.
295. Johnson, L.K., Killian, C.M., Brookhart, M., New Pd(II)- and Ni(II)-based catalysts for polymerization of ethylene and α-olefins. J Am Chem Soc 117 (1995), 6414–6415.
296. Killian, C.M., Tempel, D.J., Johnson, L.K., Brookhart, M., Living polymerization of α-olefins using Ni(II)-α-diimine catalysts. Synthesis of new block polymers based on α-olefins. J Am Chem Soc 118 (1996), 11664–11665.
297. Macchioni, A., Magistrato, A., Orabona, I., Ruffo, F., Rothlisberger, U., Zuccaccia, C., Direct observation of an equilibrium between two anion-cation orientations in olefin Pt(II) complex ion pairs by HOESY NMR spectroscopy. New J Chem 27 (2003), 455–458.
298. Cohen, Y., Avram, L., Frish, L., Diffusion NMR spectroscopy in supramolecular and combinatorial chemistry: an old parameter—new insights. Angew Chem Int Ed 44 (2005), 520–554.
299. Pregosin, P.S., Applications of NMR diffusion methods with emphasis on ion pairing in inorganic chemistry: a mini-review. Magn Reson Chem 55 (2017), 405–413.
300. Pregosin, P.S., Ion pairing using PGSE diffusion methods. Prog Nucl Magn Reson Spectrosc 49 (2006), 261–288.
301. Crabtree, R., The Organometallic Chemistry of the Transition Metals. Sixth Edit. 2014, Wiley, Hoboken, NJ.
302. Chen, Y.-X., Marks, T.J., “Constrained Geometry” dialkyl catalysts. Efficient syntheses, C − H bond activation chemistry, monomer − dimer equilibration, and α-olefin polymerization catalysis. Organometallics 16 (1997), 3649–3657.
303. Ciancaleoni, G., Fraldi, N., Budzelaar, P.H.M., Busico, V., Macchioni, A., Activation of a bis(phenoxy-amine) precatalyst for olefin polymerisation: first evidence for an outer sphere ion pair with the methylborate counterion. Dalton Trans, 2009, 8824–8827.
304. Zaccaria, F., Zuccaccia, C., Cipullo, R., et al. Toluene and α-olefins as radical scavengers: direct NMR evidence for homolytic chain transfer mechanism leading to benzyl and “dormant” titanium allyl complexes. Organometallics 37 (2018), 4189–4194.
305. Rocchigiani, L., Macchioni, A., Disclosing the multi-faceted world of weakly interacting inorganic systems by means of NMR spectroscopy. Dalton Trans 45 (2016), 2785–2790.
306. Ciancaleoni, G., Fraldi, N., Budzelaar, P.H.M., Busico, V., Cipullo, R., Macchioni, A., Structure − activity relationship in olefin polymerization catalysis: is entropy the key?. J Am Chem Soc 132 (2010), 13651–13653.
307. Chien, J.C.W., Song, W., Rausch, M.D., Polymerization of propylene by zirconocenium catalysts with different counter-ions. J Polym Sci Part A Polym Chem 32 (1994), 2387–2393.
308. Zhou, J., Lancaster, S.J., Walker, D.A., Beck, S., Thornton-Pett, M., Bochmann, M., Synthesis, structures, and reactivity of weakly coordinating anions with delocalized borate structure: effects in metallocene polymerization catalysts. J Am Chem Soc 123 (2001), 223–237.
309. + in the presence of a series of novel, weakly coordinating counteranions. J Polym Sci Part A Polym Chem 40 (2002), 3302–3311.
310. -: evidence for monomer-dependent early or late transition states. Chem Commun, 2004, 542–543.
311. Zuccaccia, D., Bellachioma, G., Cardaci, G., et al. Interionic structure of ion pairs and ion quadruples of half-sandwich ruthenium(II) salts bearing α-diimine ligands. Organometallics 26 (2007), 3930–3946.
312. Manz, T.A., Sharma, S., Phomphrai, K., et al. Quantitative effects of ion pairing and sterics on chain propagation kinetics for 1-hexene polymerization catalyzed by mixed Cp′/ArO complexes. Organometallics 27 (2008), 5504–5520.
313. Gao, Y., Chen, J., Wang, Y., et al. Highly branched polyethylene oligomers via group IV-catalysed polymerization in very nonpolar media. Nat Catal 2 (2019), 236–242.
314. +: a combined density functional theory and molecular mechanism study. Organometallics 23 (2004), 104–116.
315. Rowley, C.N., Woo, T.K., Counteranion effects on the zirconocene polymerization catalyst olefin complex from QM/MM molecular dynamics simulations. Organometallics 30 (2011), 2071–2074.
316. Correa, A., Cavallo, L., Dynamic properties of metallocenium ion pairs in solution by atomistic simulations. J Am Chem Soc 128 (2006), 10952–10959.
317. Matsumoto, K., Takayanagi, M., Sankaran, S.K., Koga, N., Nagaoka, M., Role of the counteranion in the reaction mechanism of propylene polymerization catalyzed by a (pyridylamido)hafnium(IV) complex. Organometallics 37 (2018), 343–349.
318. Matsumoto, K., Sandhya, K.S., Takayanagi, M., Koga, N., Nagaoka, M., An active site opening mechanism in a (pyridylamide)hafnium(IV) ion pair catalyst: an associative mechanism. Organometallics 35 (2016), 4099–4105.
319. Lanza, G., Fragalà, I.L., Marks, T.J., Energetic, structural, and dynamic aspects of ethylene polymerization mediated by homogeneous single-site “constrained geometry catalysts” in the presence of cocatalyst and solvation: an investigation at the ab initio quantum chemical level. Organometallics 21 (2002), 5594–5612.
320. Lanza, G., Fragalà, I.L., Marks, T.J., Highly electrophilic olefin polymerization catalysts. counteranion and solvent effects on constrained geometry catalyst ion pair structure and reactivity. J Am Chem Soc 120 (1998), 8257–8258.
321. Laine, A., Coussens, B.B., Hirvi, J.T., et al. Effect of ligand structure on olefin polymerization by a metallocene/borate catalyst: a computational study. Organometallics 34 (2015), 2415–2421.
322. 3]-catalyzed polymerization of 1-hexene. J Am Chem Soc 123 (2001), 11193–11207.
323. Landis, C.R., Christianson, M.D., Metallocene-catalyzed alkene polymerization and the observation of Zr-allyls. Proc Natl Acad Sci 103 (2006), 15349–15354.
324. 2]-catalyzed 1-hexene polymerization. J Am Chem Soc 132 (2010), 558–566.
325. 13C hyperpolarized NMR. J Am Chem Soc 137 (2015), 6965–6971.
326. Switzer, J.M., Pletcher, P.D., Steelman, D.K., et al. Quantitative modeling of the temperature dependence of the kinetic parameters for zirconium amine bis(phenolate) catalysts for 1-hexene polymerization. ACS Catal 8 (2018), 10407–10418.
327. 3]-catalyzed polymerization of 1-hexene by direct observation. J Am Chem Soc 132 (2010), 11461–11463.
328. Moscato, B.M., Zhu, B., Landis, C.R., Mechanistic investigations into the behavior of a labeled zirconocene polymerization catalyst. Organometallics 31 (2012), 2097–2107.
329. Chen, M.-C., Roberts, J.A.S., Marks, T.J., Marked counteranion effects on single-site olefin polymerization processes. Correlations of ion pair structure and dynamics with polymerization activity, chain transfer, and syndioselectivity. J Am Chem Soc 126 (2004), 4605–4625.
330. 2 complex during ethylene/1-hexene copolymerization. Cat Com 7 (2006), 721–727.
331. Price, C.J., Chen, H.-Y., Launer, L.M., Miller, S.A., Weakly coordinating cations as alternatives to weakly coordinating anions. Angew Chem Int Ed 48 (2009), 956–959.
332. 1-symmetric metallocene catalysts. Organometallics 25 (2006), 3576–3592.
333. Irwin, L.J., Reibenspies, J.H., Miller, S.A., A sterically expanded “constrained geometry catalyst” for highly active olefin polymerization and copolymerization: an unyielding comonomer effect. J Am Chem Soc 126 (2004), 16716–16717.
334. +: an alkyl zirconocenium cation stabilized by steric shielding against interaction with ancillary ligands. Organometallics 24 (2005), 867–871.
335. 4. Organometallics 14 (1995), 5005–5007.
336. Resconi, L., Piemontesi, F., Franciscono, G., Abis, L., Fiorani, T., Olefin polymerization at bis(pentamethylcyclopentadienyl)zirconium and -hafnium centers: chain-transfer mechanisms. J Am Chem Soc 114 (1992), 1025–1032.
337. + cations with alkenes. J Am Chem Soc 118 (1996), 11244–11253.
338. Feichtinger, D., Plattner, D.A., Chen, P., Ziegler − natta-like olefin oligomerization by alkylzirconocene cations in an electrospray ionization tandem mass spectrometer. J Am Chem Soc 120 (1998), 7125–7126.
339. Manz, T.A., Caruthers, J.M., Sharma, S., et al. Structure–activity correlation for relative chain initiation to propagation rates in single-site olefin polymerization catalysis. Organometallics 31 (2012), 602–618.
340. 3. Chem A Eur J 22 (2016), 11196–11200.
341. Mayr, H., Bug, T., Gotta, M.F., et al. Reference scales for the characterization of cationic electrophiles and neutral nucleophiles. J Am Chem Soc 123 (2001), 9500–9512.
342. Ofial, A.R., Benzhydrylium and tritylium ions: complementary probes for examining ambident nucleophiles. Pure Appl Chem, 87, 2015, 341.
343. Mayr, H., Kempf, B., Ofial, A.R., π-Nucleophilicity in carbon − carbon bond-forming reactions. Acc Chem Res 36 (2003), 66–77.
344. Zaccaria, F., Cipullo, R., Budzelaar, P.H.M., Busico, V., Ehm, C., Backbone rearrangement during olefin capture as the rate limiting step in molecular olefin polymerization catalysis and its effect on comonomer affinity. J Polym Sci Part A Polym Chem 55 (2017), 2807–2814.
345. 1-symmetric CGC titanium catalyst centers. J Am Chem Soc 129 (2007), 7327–7338.
346. 2-symmetrical zirconium catalyst. J Am Chem Soc 122 (2000), 10706–10707.
347. Zuccaccia, C., Macchioni, A., Busico, V., et al. Intra- and intermolecular NMR studies on the activation of arylcyclometallated hafnium pyridyl-amido olefin polymerization precatalysts. J Am Chem Soc 130 (2008), 10354–10368.
348. Gao, Y., Mouat, A.R., Motta, A., et al. Pyridylamido Bi-hafnium olefin polymerization catalysis: conformationally supported Hf···Hf enchainment cooperativity. ACS Catal 5 (2015), 5272–5282.
349. Annunziata, L., Roisnel, T., Razavi, A., Carpentier, J.-F., Kirillov, E., Conformationally dynamic titanium and zirconium cationic complexes of bis(naphthoxy)pyridine ligands: structure, “oscillation” and olefin polymerization catalysis. Dalton Trans 46 (2017), 3150–3159.
350. Ciancaleoni, G., Fraldi, N., Budzelaar, P.H.M., Busico, V., Macchioni, A., Structure and dynamics in solution of bis(phenoxy-amine)zirconium catalysts for olefin polymerization. Organometallics 30 (2011), 3096–3105.
351. 2-symmetric octahedral Zr(IV) complexes with tetradentate [ONNO]-type ligands. Macromol Rapid Commun 22 (2001), 1405–1410.
352. Busico, V., Cipullo, R., Pellecchia, R., Ronca, S., Roviello, G., Talarico, G., Design of stereoselective Ziegler–Natta propene polymerization catalysts. Proc Natl Acad Sci 103 (2006), 15321–15326.
353. Ciancaleoni, G., Fraldi, N., Cipullo, R., Busico, V., Macchioni, A., Budzelaar, P.H.M., Structure/properties relationship for bis(phenoxyamine)Zr(IV)-based olefin polymerization catalysts: a simple DFT model to predict catalytic activity. Macromolecules 45 (2012), 4046–4053.
354. Zhang, Y., Keaton, R.J., Sita, L.R., Degenerative transfer living Ziegler − Natta polymerization: application to the synthesis of monomodal stereoblock polyolefins of narrow polydispersity and tunable block length. J Am Chem Soc 125 (2003), 9062–9069.
355. Zhang, Y., Sita, L.R., Stereospecific living Ziegler − Natta polymerization via rapid and reversible chloride degenerative transfer between active and dormant sites. J Am Chem Soc 126 (2004), 7776–7777.
356. 2[N(Et)C(Me)N(t-Bu)] (R = Me and i-Bu) for the stereospecific living and degenerative transfer living Ziegler–Natta polymerization of α-olefins. Adv Synth Catal 347 (2005), 426–432.
357. Xiong, S., Steelman, D.K., Medvedev, G.A., Delgass, W.N., Abu-Omar, M.M., Caruthers, J.M., Selective degenerative benzyl group transfer in olefin polymerization. ACS Catal 4 (2014), 1162–1170.
358. Bochmann, M., Lancaster, S.J., Base-free cationic zirconium benzyl complexes as highly active polymerization catalysts. Organometallics 12 (1993), 633–640.
359. Ustynyuk, L.Y., Fushman, E.A., Lalayan, S.S., Nifantév, I.E., Zirconocene catalysts for olefin polymerization: a comparative DFT study of systems with Al- and B-containing activators. J Organomet Chem 700 (2012), 166–179.
360. Cai, Z., Ikeda, T., Akita, M., Shiono, T., Substituent effects of tert-butyl groups on fluorenyl ligand in syndiospecific living polymerization of propylene with ansa-fluorenylamidodimethyltitanium complex. Macromolecules 38 (2005), 8135–8139.
361. Busico, V., Cipullo, R., Pellecchia, R., Talarico, G., Razavi, A., Hafnocenes and MAO: beware of trimethylaluminum!. Macromolecules 42 (2009), 1789–1791.
362. Song, F., Cannon, R.D., Lancaster, S.J., Bochmann, M., Activator effects in metallocene-based alkene polymerisations: unexpectedly strong dependence of catalyst activity on trityl concentration. J Mol Catal A Chem 218 (2004), 21–28.
363. Vathauer, M., Kaminsky, W., Extremely active polymerizations of propene by bisindenylzirconocenes and tetra(pentafluorophenyl)-borate. Polymer 42 (2001), 4017–4024.
364. 4] initiator. Organometallics 20 (2001), 5205–5211.
365. Alonso-Moreno, C., Lancaster, S.J., Zuccaccia, C., Macchioni, A., Bochmann, M., Evidence for mixed-ion clusters in metallocene catalysts: influence on ligand exchange dynamics and catalyst activity. J Am Chem Soc 129 (2007), 9282–9283.
366. 4). Organometallics 27 (2008), 5474–5487.
367. Beck, S., Lieber, S., Schaper, F., Geyer, A., Brintzinger, H.-H., Anion exchange in alkyl − zirconocene borate ion pairs. Are solvated alkyl − zirconocene cations relevant intermediates?. J Am Chem Soc 123 (2001), 1483–1489.
368. 2 complexes as a possible deactivation pathway in polymerization catalysis. J Organomet Chem 484 (1994), c10–c12.
369. Soga, K., Ban, H.T., Uozumi, T., Synthesis of a dinuclear ansa-zirconocene catalyst having a biphenyl bridge and application to ethene polymerization. J Mol Catal A Chem 128 (1998), 273–278.
370. Yan, X., Chernega, A., Green, M.L.H., Sanders, J., Souter, J., Ushioda, T., Homo- and hetero-binuclear ansa-metallocenes of the group 4 transition metals as homogeneous co-catalysts for the polymerisation of ethene and propene. J Mol Catal A Chem 128 (1998), 119–141.
371. Spaleck, W., Küber, F., Bachmann, B., Fritze, C., Winter, A., New bridged zirconocenes for olefin polymerization: binuclear and hybrid structures. J Mol Catal A Chem 128 (1998), 279–287.
372. Abramo, G.P., Li, L., Marks, T.J., Polynuclear catalysis: enhancement of enchainment cooperativity between different single-site olefin polymerization catalysts by ion pairing with a binuclear cocatalyst. J Am Chem Soc 124 (2002), 13966–13967.
373. Li, H., Li, L., Marks, T.J., Liable-Sands, L., Rheingold, A.L., Catalyst/cocatalyst nuclearity effects in single-site olefin polymerization. Significantly enhanced 1-octene and isobutene comonomer enchainment in ethylene polymerizations mediated by binuclear catalysts and cocatalysts. J Am Chem Soc 125 (2003), 10788–10789.
374. Suo, H., Solan, G.A., Ma, Y., Sun, W.-H., Developments in compartmentalized bimetallic transition metal ethylene polymerization catalysts. Coord Chem Rev 372 (2018), 101–116.
375. Delferro, M., Marks, T.J., Multinuclear olefin polymerization catalysts. Chem Rev 111 (2011), 2450–2485.
376. Ainooson, M., Meyer, F., Bimetallic approaches in olefin polymerization and metathesis. Reedijk, J., Poeppelmeier, K., (eds.) Comprehensive Inorganic Chemistry II, 2013, Elsevier, Amsterdam, NL, 433–458.
377. McInnis, J.P., Delferro, M., Marks, T.J., Multinuclear group 4 catalysis: olefin polymerization pathways modified by strong metal–metal cooperative effects. Acc Chem Res 47 (2014), 2545–2557.
378. Buchwalter, P., Rosé, J., Braunstein, P., Multimetallic catalysis based on heterometallic complexes and clusters. Chem Rev 115 (2015), 28–126.
379. Zuccaccia, C., Macchioni, A., Sian, L., Effect of formation of ionic aggregates higher than ion pairs on the kinetics of a single olefin insertion into the Zr-C bond. Abstracts of Papers, 253rd ACS National Meeting & Exposition. San Francisco, CA, 2017 April.
380. Sian L, Macchioni A, Zuccaccia C. Manuscript in preparation.
381. Mohammed, M., Nele, M., Al-Humydi, A., Xin, S., Stapleton, R.A., Collins, S., Counterion effects on propylene polymerization using two-state ansa-metallocene complexes. J Am Chem Soc 125 (2003), 7930–7941.
382. 1-symmetric group 4 metallocenes as catalysts for stereoregular α-olefin polymerization. Metal, ancillary ligand, and counteranion effects. J Am Chem Soc 117 (1995), 12114–12129.
383. Min, E.Y., Byers, J.A., Bercaw, J.E., Catalyst site epimerization during the kinetic resolution of chiral r-olefins by polymerization. Organometallics 27 (2008), 2179–2188.
384. Chen, M.-C., Marks, T.J., Strong ion pairing effects on single-site olefin polymerization: mechanistic insights in syndiospecific propylene enchainment. J Am Chem Soc 123 (2001), 11803–11804.
385. s-Symmetric ansa-Zirconocenes. Macromolecules 36 (2003), 4258–4261.
386. Shiomura, T., Asanuma, T., Inoue, N., Inversion of stereoselectivity in a metallocene catalyst. Macromol Rapid Commun 17 (1996), 9–14.
387. Castro, L., Therukauff, G., Vantomme, A., et al. A theoretical outlook on the stereoselectivity origins of isoselective zirconocene propylene polymerization catalysts. Chem A Eur J 24 (2018), 10784–10792.
388. Luo, L., Marks, T.J., Ziegler—Natta catalyst activation. Thermodynamic and kinetic aspects of metallocenium ion-pair formation, dissociation, and structural reorganization. Top Catal 7 (1999), 97–106.
389. Perrin, C.L., Dwyer, T.J., Application of two-dimensional NMR to kinetics of chemical exchange. Chem Rev 90 (1990), 935–967.
390. Nikitin, K., O'Gara, R., Mechanisms and beyond: elucidation of fluxional dynamics by exchange NMR spectroscopy. Chem A Eur J 25 (2019), 4551–4589.
391. Camara, J.M., Petros, R.A., Norton, J.R., Zirconium-catalyzed carboalumination of α-olefins and chain growth of aluminum alkyls: kinetics and mechanism. J Am Chem Soc 133 (2011), 5263–5273.
392. Henderson, L.D., Piers, W.E., Ion pair symmetrization in metallocenium cations partnered with diborane derived borate counteranions. J Organomet Chem 692 (2007), 4661–4668.
393. 2. Organometallics 19 (2000), 1841–1849.
394. 3 with bisindenyl dimethyl zirconium complexes. Chem A Eur J 11 (2005), 650–661.
395. Wilson, P.A., Hannant, M.H., Wright, J.A., Cannon, R.D., Bochmann, M., Anion Influence in metallocene-based olefin polymerisation catalysts. Macromol Symp 236 (2006), 100–110.
396. Brandow, C.G., Mendiratta, A., Bercaw, J.E., Ancillary ligand and olefin substituent effects on olefin dissociation for cationic zirconocene complexes bearing a coordinated pendant olefin. Organometallics 20 (2001), 4253–4261.
397. 0 zirconium − alkyl − alkene complex. Organometallics 19 (2000), 3970–3977.
398. Beswick, C.L., Marks, T.J., Significant zirconium − alkyl group effects on ion pair formation thermodynamics and structural reorganization dynamics in zirconocenium alkyls. Organometallics 18 (1999), 2410–2412.
399. -derived Zr and Hf metallocenium ion-pairs. J Am Chem Soc 122 (2000), 10358–10370.
400. 2C(Cp)(Flu)Zr systems. Macromolecules 36 (2003), 8171–8177.
401. Graf, M., Angermund, K., Fink, G., Thiel, W., Jensen, V.R., Site epimerization in ansa-zirconocene polymerization catalysts. J Organomet Chem 691 (2006), 4367–4378.
402. Dunlop-Brière, A.F., Budzelaar, P.H.M., Baird, M.C., α- and β-agostic alkyl–titanocene complexes. Organometallics 31 (2012), 1591–1594.
403. 3 analogues. Organometallics 34 (2015), 2356–2368.
404. Nele, M., Mohammed, M., Xin, S., Collins, S., Dias, M.L., Pinto, J.C., Two-state models for propylene polymerization using metallocene catalysts. 2. Application to ansa-metallocene catalyst systems. Macromolecules 34 (2001), 3830–3841.
405. 4) structures and the implications for “continuous” or “Intermittent” alkene polymerization mechanisms. Organometallics 24 (2005), 1315–1328.
406. Beck, S., Geyer, A., Brintzinger, H.-H., Diffusion coefficients of zirconocene-borate ion pairs studied by pulsed field-gradient NMR-evidence for ion quadruples in benzene solutions. Chem Commun, 1999, 2477–2478.
407. Rieger, B., Troll, C., Preuschen, J., Ultrahigh molecular weight polypropene elastomers by high activity “dual-side” hafnocene catalysts. Macromolecules 35 (2002), 5742–5743.
408. Crabtree, R.H., Deactivation in homogeneous transition metal catalysis: causes, avoidance, and cure. Chem Rev 115 (2015), 127–150.
409. Ehm, C., Cipullo, R., Passaro, M., Zaccaria, F., Budzelaar, P.H.M., Busico, V., Chain transfer to solvent in propene polymerization with Ti Cp-phosphinimide catalysts: evidence for chain termination via Ti–C bond homolysis. ACS Catal 6 (2016), 7989–7993.
410. Ehm, C., Budzelaar, P.H.M., Busico, V., Metal–carbon bond strengths under polymerization conditions: 2,1-insertion as a catalyst stress test. J Catal 351 (2017), 146–152.
411. Zaccaria, F., Ehm, C., Budzelaar, P.H.M., Busico, V., Cipullo, R., Catalyst mileage in olefin polymerization: the peculiar role of toluene. Organometallics 37 (2018), 2872–2879.
412. Wu, F., Dash, A.K., Jordan, R.F., Structures and reactivity of Zr(IV) chlorobenzene complexes. J Am Chem Soc 126 (2004), 15360–15361.
413. Ma, K., Piers, W.E., Parvez, M., Competitive ArC − H and ArC − X (X = Cl, Br) activation in halobenzenes at cationic titanium centers. J Am Chem Soc 128 (2006), 3303–3312.
414. Ma, K., Piers, W.E., Gao, Y., Parvez, M., Isolation and characterization of a monomeric cationic titanium hydride. J Am Chem Soc 126 (2004), 5668–5669.
415. Bolton, P.D., Clot, E., Adams, N., Dubberley, S.R., Cowley, A.R., Mountford, P., Experimental and DFT studies of cationic imido titanium alkyls: agostic interactions and C − H bond and solvent activation reactions of isolobal analogues of group 4 metallocenium cations. Organometallics 25 (2006), 2806–2825.
416. +: elusive Intermediates during Ziegler–Natta polymerizations of alkenes. Angew Chem Int Ed 48 (2009), 3342–3345.
417. 0 zirconocene–allyl complexes. Organometallics 33 (2014), 3683–3694.
418. +: the role of such species in metallocene catalyst deactivation to allylic species. J Am Chem Soc 130 (2008), 454–456.
419. 3). Organometallics 20 (2001), 2088–2092.
420. Suzuki, Y., Yasumoto, T., Mashima, K., Okuda, J., Hafnocene catalysts for selective propylene oligomerization: efficient synthesis of 4-methyl-1-pentene by β-methyl transfer. J Am Chem Soc 128 (2006), 13017–13025.
421. Zuccaccia, C., Tensi, L., Kuhlman, R.L., Gies, A.P., Macchioni, A., C–H activation and olefin insertion as sources of multiple sites in olefin polymerization catalyzed by CpAlkylHf(IV) complexes. ACS Catal 7 (2017), 563–567.
422. + and a simple solution that yields a catalyst for the living polymerization of 1-hexene. Organometallics 20 (2001), 1056–1058.
423. Gies, A.P., Kuhlman, R.L., Zuccaccia, C., Macchioni, A., Keaton, R.J., Mass spectrometric mechanistic investigation of ligand modification in hafnocene-catalyzed olefin polymerization. Organometallics 36 (2017), 3443–3455.
424. Mehdiabadi, S., Soares, J.B.P., Brinen, J., Atypical multiple site behavior of hafnocene catalysts in ethylene/1-hexene copolymerization using trioctylaluminum and borate. Macromolecules 51 (2018), 7061–7076.
425. Marquet, N., Kirillov, E., Roisnel, T., Razavi, A., Carpentier, J.-F., Group 4 metal complexes of fluorous (Di)alkoxide-(Di)imino ligands: synthesis, structure, olefin polymerization catalysis, and decomposition pathways. Organometallics 28 (2009), 606–620.
426. Arriola, D.J., Carnahan, E.M., Hustad, P.D., Kuhlman, R.L., Wenzel, T.T., Catalytic Production of Olefin Block Copolymers via Chain Shuttling Polymerization. Science 312 (2006), 714 LP–719.
427. Zuccaccia, C., Busico, V., Cipullo, R., et al. On the first insertion of α-olefins in hafnium pyridyl-amido polymerization catalysts. Organometallics 28 (2009), 5445–5458.
428. 3). Angew Chem Int Ed 53 (2014), 2157–2161.
429. Rocchigiani, L., Busico, V., Pastore, A., Macchioni, A., Comparative NMR study on the reactions of Hf(IV) organometallic complexes with Al/Zn alkyls. Organometallics 35 (2016), 1241–1250.
430. Sita, L.R., Ex Uno Plures (“Out of One, Many”): new paradigms for expanding the range of polyolefins through reversible group transfers. Angew Chem Int Ed 48 (2009), 2464–2472.
431. Amin, S.B., Marks, T.J., Versatile pathways for in situ polyolefin functionalization with heteroatoms: catalytic chain transfer. Angew Chem Int Ed 47 (2008), 2006–2025.
432. Valente, A., Mortreux, A., Visseaux, M., Zinck, P., Coordinative chain transfer polymerization. Chem Rev 113 (2013), 3836–3857.
433. Froese, R.D.J., Hustad, P.D., Kuhlman, R.L., Wenzel, T.T., Mechanism of activation of a hafnium pyridyl − amide olefin polymerization catalyst: ligand modification by monomer. J Am Chem Soc 129 (2007), 7831–7840.
434. Busico, V., Cipullo, R., Pellecchia, R., et al. “Uni et Trini”: in situ diversification of (pyridylamide)hafnium(IV) catalysts. Macromolecules 42 (2009), 4369–4373.
435. Domski, G.J., Lobkovsky, E.B., Coates, G.W., Polymerization of α-olefins with pyridylamidohafnium catalysts: living behavior and unexpected isoselectivity from a Cs-symmetric catalyst precursor. Macromolecules 40 (2007), 3510–3513.
436. Vittoria, A., Busico, V., Cannavacciuolo, F.D., Cipullo, R., Molecular kinetic study of “chain shuttling” olefin copolymerization. ACS Catal 8 (2018), 5051–5061.
437. Cueny, E.S., Landis, C.R., Zinc-mediated chain transfer from hafnium to aluminum in the hafnium-pyridyl amido-catalyzed polymerization of 1-octene revealed by job plot analysis. Organometallics 38 (2019), 926–932.
438. Johnson, H.C., Cueny, E.S., Landis, C.R., Chain transfer with dialkyl zinc during hafnium–pyridyl amido-catalyzed polymerization of 1-octene: relative rates, reversibility, and kinetic models. ACS Catal 8 (2018), 4178–4188.
439. Frazier, K.A., Froese, R.D., He, Y., et al. Pyridylamido hafnium and zirconium complexes: synthesis, dynamic behavior, and ethylene/1-octene and propylene polymerization reactions. Organometallics 30 (2011), 3318–3329.
440. Zhang, J., Motta, A., Gao, Y., et al. Cationic pyridylamido adsorbate on brønsted acidic sulfated zirconia: a molecular supported organohafnium catalyst for olefin homo- and co-polymerization. ACS Catal 8 (2018), 4893–4901.
441. Gao, Y., Chen, X., Zhang, J., Chen, J., Lohr, T.L., Marks, T.J., Catalyst nuclearity effects on stereo- and regioinduction in pyridylamidohafnium-catalyzed propylene and 1-octene polymerizations. Macromolecules 51 (2018), 2401–2410.
442. Cueny, E.S., Johnson, H.C., Anding, B.J., Landis, C.R., Mechanistic studies of hafnium-pyridyl amido-catalyzed 1-octene polymerization and chain transfer using quench-labeling methods. J Am Chem Soc 139 (2017), 11903–11912.
443. Xu, J., Eagan, J.M., Kim, S.-S., et al. Compatibilization of isotactic polypropylene (iPP) and high-density polyethylene (HDPE) with iPP–PE multiblock copolymers. Macromolecules 51 (2018), 8585–8596.
444. De Rosa, C., Di Girolamo, R., Talarico, G., Expanding the origin of stereocontrol in propene polymerization catalysis. ACS Catal 6 (2016), 3767–3770.
445. Domski, G.J., Eagan, J.M., De Rosa, C., et al. Combined experimental and theoretical approach for living and isoselective propylene polymerization. Acs Catal 7 (2017), 6930–6937.
446. Invergo, A.M., Liu, S., Dicken, R.D., et al. How close is too close? Polymerization behavior and monomer-dependent reorganization of a bimetallic salphen organotitanium catalyst. Organometallics 37 (2018), 2429–2436.
447. Makio, H., Prasad, A.V., Terao, H., Saito, J., Fujita, T., Isospecific propylene polymerization with in situ generated bis(phenoxy-amine)zirconium and hafnium single site catalysts. Dalton Trans 42 (2013), 9112–9119.
448. Knight, P.D., Clarke, A.J., Kimberley, B.S., Jackson, R.A., Scott, P., Problems and solutions for alkene polymerisation catalysts incorporating Schiff-bases; migratory insertion and radical mechanisms of catalyst deactivation. Chem Commun, 2002, 352–353.
449. 2 Schiff-base complexes of titanium with a biaryl backbone: highly diastereoselective migratory insertion of alkyl at imine. J Chem Soc Dalton Trans, 2000, 3340–3346.
450. Knight, P.D., O'Shaughnessy, P.N., Munslow, I.J., Kimberley, B.S., Scott, P., Biaryl-bridged Schiff base complexes of zirconium alkyls: synthesis structure and stability. J Organomet Chem 683 (2003), 103–113.
451. Knight, P.D., Clarkson, G., Hammond, M.L., Kimberley, B.S., Scott, P., Radical and migratory insertion reaction mechanisms in Schiff base zirconium alkyls. J Organomet Chem 690 (2005), 5125–5144.
452. Cariou, R., Gibson, V.C., Tomov, A.K., White, A.J.P., Group 4 metal complexes bearing new tridentate (NNO) ligands: benzyl migration and formation of unusual C–C coupled products. J Organomet Chem 694 (2009), 703–716.
453. Axenov, K.V., Klinga, M., Lehtonen, O., Koskela, H.T., Leskelä, M., Repo, T., Hafnium bis(phenoxyimino) dibenzyl complexes and their activation toward olefin polymerization. Organometallics 26 (2007), 1444–1460.
454. Romain, C., Miqueu, K., Sotiropoulos, J.-M., Bellemin-Laponnaz, S., Dagorne, S., Non-innocent behavior of a tridentate NHC chelating ligand coordinated onto a zirconium(IV) center. Angew Chem 122 (2010), 2244–2247.
455. Tsurugi, H., Matsuo, Y., Yamagata, T., Mashima, K., Intramolecular benzylation of an imino group of tridentate 2,5-Bis(N-aryliminomethyl)pyrrolyl ligands bound to zirconium and hafnium gives amido-pyrrolyl complexes that catalyze ethylene polymerization. Organometallics 23 (2004), 2797–2805.
456. De Waele, P., Jazdzewski, B.A., Klosin, J., et al. Synthesis of hafnium and zirconium imino − amido complexes from bis-imine ligands. A new family of olefin polymerization catalysts. Organometallics 26 (2007), 3896–3899.
457. Keaton, R.J., Jayaratne, K.C., Fettinger, J.C., Sita, L.R., Structural characterization of zirconium cations derived from a living Ziegler − Natta polymerization system: new insights regarding propagation and termination pathways for homogeneous catalysts. J Am Chem Soc 122 (2000), 12909–12910.
458. Jayaratne, K.C., Sita, L.R., Direct methyl group exchange between cationic zirconium Ziegler − Natta initiators and their living polymers: ramifications for the production of stereoblock polyolefins. J Am Chem Soc 123 (2001), 10754–10755.
459. Ijpeij, E.G., Coussens, B., Zuideveld, M.A., et al. Synthesis, solid state and DFT structure and olefin polymerization capability of a unique base-free dimeric methyl titanium dication. Chem Commun 46 (2010), 3339–3341.
460. Coates, G.W., Waymouth, R.M., Oscillating stereocontrol: a strategy for the synthesis of thermoplastic elastomeric polypropylene. Science 267 (1995), 217–219.
461. Wilmes, G.M., Polse, J.L., Waymouth, R.M., Influence of cocatalyst on the stereoselectivity of unbridged 2-phenylindenyl metallocene catalysts. Macromolecules 35 (2002), 6766–6772.
462. Wilmes, G.M., France, M.B., Lynch, S.R., Waymouth, R.M., Effects of ligand substitutions on the rotation rate of indenyl ligands in bis(2-arylindenyl)zirconocenes by NMR line-shape analysis and relaxation in the rotating frame. Organometallics 23 (2004), 2405–2411.
463. Lincoln, A.L., Wilmes, G.M., Waymouth, R.M., Dynamic NMR studies of cationic bis(2-phenylindenyl)zirconium pyridyl complexes: evidence for syn conformers in solution. Organometallics 24 (2005), 5828–5835.
464. Busico, V., Van Axel, C.V., Aprea, P., et al. “Oscillating” metallocene catalysts: what stops the oscillation?. J Am Chem Soc 125 (2003), 5451–5460.
465. Li, G., Lamberti, M., Roviello, G., Pellecchia, C., New titanium and hafnium complexes bearing [− NNN–] pyrrolylpyridylamido ligands as olefin polymerization catalysts. Organometallics 31 (2012), 6772–6778.
466. Luconi, L., Rossin, A., Tuci, G., et al. Facing unexpected reactivity paths with ZrIV–pyridylamido polymerization catalysts. Chem A Eur J 18 (2012), 671–687.
467. IV complexes: a further level of complexity for the elusive active species of pyridylamido olefin polymerisation catalysts. Chem A Eur J 20 (2014), 232–244.
468. Lenton, T.N., Bercaw, J.E., Panchenko, V.N., et al. Formation of trivalent zirconocene complexes from ansa-zirconocene-based olefin-polymerization precatalysts: an EPR- and NMR-spectroscopic study. J Am Chem Soc 135 (2013), 10710–10719.