A bidentate ligand with appended hydrogen bond donors: Synthesis and structure of four-coordinate metal complexes with bis[(tert-butyl)aminocarbonyl]-1,2-diaminoethane

Inorganica Chimica Acta

Volumn 341, Issue , 2002, Pages 77-84

  MacBeth, Cora E ^a   Larsen, Peter L ^a   Sorrell, Thomas N ^b   Powell, Douglas ^a   Borovik, A S ^a  

^a UNIVERSITY OF KANSAS   (United States)

^b University of North Carolina at Chapel Hill   (United States)

Author keywords

Bidentate ligand; Hydrogen bond donors; Metal complexes

Indexed keywords

CHELATION; COMPLEXATION; LIGANDS; METAL COMPLEXES; METAL IONS; PROTEINS; SYNTHESIS (CHEMICAL); TRANSITION METAL COMPOUNDS; TRANSITION METALS;

BIDENTATE LIGANDS; COORDINATE COMPLEXES; COORDINATION SPHERE; FIRST ROW TRANSITION METALS; HYDROGEN BOND DONORS; NON-COVALENT INTERACTION; TETRAHEDRAL COORDINATION GEOMETRY; X-RAY DIFFRACTION STUDIES;

HYDROGEN BONDS;

BIS[(TERT BUTYL)AMINOCARBONYL] 1,2 DIAMINOETHANE; COBALT; ETHYLENEDIAMINE DERIVATIVE; IRON; LIGAND; METAL COMPLEX; UNCLASSIFIED DRUG; ZINC;

ARTICLE; CRYSTAL STRUCTURE; CRYSTALLIZATION; GEOMETRY; HYDROGEN BOND; PROTON TRANSPORT; SYNTHESIS; X RAY DIFFRACTION;

EID: 0037058813     PISSN: 00201693     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0020-1693(02)01181-7     Document Type: Article

References (48)

1. Lipscomb W.N., Sträter N. Chem. Rev. 96:1996;2375. and references therein.
2. Christianson D.W., Cox J.D. Annu. Rev. Biochem. 68:1999;33.
3. Ozaki S., Roach M.P., Matsui T., Watanabe Y. Acc. Chem. Res. 34:2001;818.
4. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
5. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
6. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
7. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
8. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
9. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
10. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
11. Representative examples of H-bonding systems: (a) R. Quinn, J. Mercer-Smith, J.N. Burstyn, J.S. Valentine, J. Am. Chem. Soc. 106 (1984) 4136; (b) G.E. Wuenschell, C. Tetreau, D. Lavalette, C.A. Reed, J. Am. Chem. Soc. 114 (1992) 3346; (c) J.P. Collman, X. Zhang, K. Wong, J.I. Brauman, J. Am. Chem. Soc. 116 (1994) 6245 d) M. Momenteau, C.A. Reed, Chem. Rev. 94 (1994) 659; (e) C.K. Chang, Y. Liang, G. Avilés, S.-M. Peng, J. Am. Chem. Soc. 117 (1995) 4191; (f) J.E. Kickham, S.J. Loeb, S.L. Murphy, J. Am. Chem. Soc. 115 (1993) 7031; (g) D.M. Rudkevich, W. Verboom, Z. Brzozka, M.J. Palys, W.P.R.V. Staut-hamer, G.J. Van Hummel, S. M. Franken, S. Harkema, J.F.J. Engbersen, D.N. Reinhoudt, J. Am. Chem. Soc. 116 (1994) 4341; (h) N. Kitajima, H. Komatsuzaki, S. Hikichi, M. Osawa, Y. Moro-oka, J. Am. Chem. Soc. 116 (1994) 11596.
12. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
13. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
14. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
15. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
16. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
17. Recent examples in non-heme bioinorganic chemistry: (a) M. Harata, K. Jitsukawa, H. Masuda, H. Einaga, Chem. Lett. (1995) 61; (b) A. Wada, M. Harata, K. Hasegawa, K. Jitsukawa, H. Masuda, M. Mukai, T. Kitagawa, H. Einaga, Angew. Chem., Int. Ed. Engl. 37 (1998) 798; (c) S. Ogo, S. Wada, Y. Watanabe, M. Iwase, A. Wada, M. Harata, K. Jitsukawa, H. Masuda, H. Einage, Angew. Chem., Int. Ed. Engl. 37 (1998) 2102; (d) L.M. Berreau, R.A. Allred, M.M. Makowski-Grzyska, A.M. Arif, Chem. Commun. (2000) 1423; (e) L.M. Berreau, M.M. Makowska-Grzyska, A.M. Arif, Inorg. Chem. 40 (2001) 2212; (f) J. Huang, R.L. Ostrader, A.L. Rheingold, M.A. Walters, Inorg. Chem. 34 (1995) 1090.
18. For examples of H-bonds in organometallic chemistry see: (a) W. Yao, R.H. Crabtree, Inorg. Chem. 35 (1996) 3007; (b) L.C. Lee, Jr., E. Peris, A.L. Rheingold, R.H. Crabtree, J. Am. Chem. Soc. 116 (1994) 11014; (c) E. Peris, J.C. Lee, Jr., J.R. Rambo, O. Eisenstein, R.H. Crabtree, J. Am. Chem. Soc. 117 (1995) 3485; (d) A.J. Lough, S. Park, R. Ramachandran, R.H. Morris, J. Am. Chem. Soc. 116 (1994) 8356.
19. For examples of H-bonds in organometallic chemistry see: (a) W. Yao, R.H. Crabtree, Inorg. Chem. 35 (1996) 3007; (b) L.C. Lee, Jr., E. Peris, A.L. Rheingold, R.H. Crabtree, J. Am. Chem. Soc. 116 (1994) 11014; (c) E. Peris, J.C. Lee, Jr., J.R. Rambo, O. Eisenstein, R.H. Crabtree, J. Am. Chem. Soc. 117 (1995) 3485; (d) A.J. Lough, S. Park, R. Ramachandran, R.H. Morris, J. Am. Chem. Soc. 116 (1994) 8356.
20. For examples of H-bonds in organometallic chemistry see: (a) W. Yao, R.H. Crabtree, Inorg. Chem. 35 (1996) 3007; (b) L.C. Lee, Jr., E. Peris, A.L. Rheingold, R.H. Crabtree, J. Am. Chem. Soc. 116 (1994) 11014; (c) E. Peris, J.C. Lee, Jr., J.R. Rambo, O. Eisenstein, R.H. Crabtree, J. Am. Chem. Soc. 117 (1995) 3485; (d) A.J. Lough, S. Park, R. Ramachandran, R.H. Morris, J. Am. Chem. Soc. 116 (1994) 8356.
21. For examples of H-bonds in organometallic chemistry see: (a) W. Yao, R.H. Crabtree, Inorg. Chem. 35 (1996) 3007; (b) L.C. Lee, Jr., E. Peris, A.L. Rheingold, R.H. Crabtree, J. Am. Chem. Soc. 116 (1994) 11014; (c) E. Peris, J.C. Lee, Jr., J.R. Rambo, O. Eisenstein, R.H. Crabtree, J. Am. Chem. Soc. 117 (1995) 3485; (d) A.J. Lough, S. Park, R. Ramachandran, R.H. Morris, J. Am. Chem. Soc. 116 (1994) 8356.
22. Franczyk T.S., Czerwinski K.R., Raymond K.N. J. Am. Chem. Soc. 114:1992;8138.
23. Walton P.H., Raymond K.N. Inorg. Chim. Acta. 240:1994;593.
24. Borovik A.S., Dewey T.M., Raymond K.N. Inorg. Chem. 32:1993;413.
25. Borovik A.S., Du Bois J., Raymond K.N. Angew. Chem., Int. Ed. Engl. 34:1995;1359.
26. Hammes B.S., Young V.G. Jr., Borovik A.S. Angew. Chem., Int. Ed. Engl. 38:1999;666.
27. Shirin Z., Hammes B.S., Young V.G. Jr., Borovik A.S. J. Am. Chem. Soc. 122:2000;1836.
28. MacBeth C.E., Golombek A.P., Young V.G. Jr., Yang C., Kuczera K., Hendrich M.P., Borovik A.S. Science. 289:2000;938.
29. MacBeth C.E., Hammes B.S., Young V.G. Jr., Borovik A.S. Inorg. Chem. 40:2001;4733.
30. Gupta R., MacBeth C.E., Young V.G. Jr., Borovik A.S. J. Am. Chem. Soc. 124:2002;1136.
31. Van Verst M.E., Bell C.L., Bauer L. Hetrocyclic Chem. 16:1979;1329.
32. The twist angle is defined as the angle between the planes containing N1-M-N2 and N3-M-N4.
33. Ray M., Hammes B.S., Yap G.P.A., Rheingold A.H., Liable-Sands L., Borovik A.S. Inorg. Chem. 37:1998;1527.
34. Ray M., Golombek A., Hendrich M.P., Young V.G. Jr., Borovik A.S. J. Am. Chem. Soc. 118:1996;6084.
35. Bu H.Z., Cao Z.C., Zhang Z.H., Zhu Z.A., Chen Y.T., Shionoya M., Kimura E. Polyhedron. 15:1996;1203.
36. Braga D., Grepioni F., Tedesco E., Biradha K., Desiraju G.R. Organometallics. 16:1997;1846. and references therein.
37. Calhorda M.J. Chem. Commun. 2000;801.
38. Collins T.J. Acc. Chem. Res. 27:1994;279.
39. Collins T.J., Nichols T.R., Uffelman E.S. J. Am. Chem. Soc. 113:1991;4709.
40. Collins T.J., Uffelman E.S. Angew. Chem., Int. Ed. Engl. 28:1989;1509.
41. Collins T.J., Powell R.D., Slebodnick C., Uffelman E.S. J. Am. Chem. Soc. 113:1991;8419.
42. Collins T.J., Kostka K.L., Münck E., Uffelman E.S. J. Am. Chem. Soc. 112:1990;5637.
43. Collins T.J., Fox B.G., Hu Z.G., Kostka K.L., Münck E., Rickard C.E.F., Wright L.J. J. Am. Chem. Soc. 114:1992;8724.
44. Horwitz C.P., Fooksman D.R., Vuocolo L.D., Gordon-Wiley S.W., Cox N.J., Collins T.J. J. Am. Chem. Soc. 120:1998;4867.
45. Plass W., Verkade J.G. J. Am. Chem. Soc. 114:1992;2275.
46. Cummins C.C., Lee J., Schrock R.R., Davis W.D. Angew. Chem., Int. Ed. Engl. 31:1992;1501.
47. Cummins C.C., Schrock R.R., Davis W.D. Inorg. Chem. 33:1994;1448. and references therein.
48. Schrock R.R. Acc. Chem. Res. 30:1997;9.