Solvated silylium cations: Structure determination by nmr spectroscopy and the nmr/ab initio/iglo method

Journal of the American Chemical Society

Volumn 118, Issue 21, 1996, Pages 5120-5131

  Arshadi, Mehrdad ^a   Johnels, Dan ^a   Edlund, Ulf ^a   Ottosson, Carl Henrik ^b   Cremer, Dieter ^b  

^a UMEÅ UNIVERSITY   (Sweden)

^b UNIVERSITY OF GOTHENBURG   (Sweden)

Author keywords

[No Author keywords available]

Indexed keywords

BINDING ENERGY; CALCULATIONS; GEOMETRY; IONS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; SILICON COMPOUNDS; SOLUTIONS; STABILITY; STRUCTURE (COMPOSITION);

AB INITIO CALCULATIONS; CHEMICAL SHIFT CALCULATIONS; SOLVATED SILYLIUM CATIONS;

ORGANOMETALLICS;

1 METHYLIMIDAZOLE; ACETONITRILE; CATION; DIMETHYL SULFOXIDE; HEMPA; PYRIDINE; SILYLIUM; SOLVENT; TRIETHYLAMINE; UNCLASSIFIED DRUG;

ARTICLE; CATION TRANSPORT; CHEMICAL BINDING; COVALENT BOND; ENERGY BALANCE; EQUILIBRIUM CONSTANT; MATHEMATICAL ANALYSIS; PROTON NUCLEAR MAGNETIC RESONANCE; SOLVATION; STEREOCHEMISTRY; TEMPERATURE SENSITIVITY;

EID: 84962406897     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9542956     Document Type: Article

References (107)

1. Weber, W. P. Silicon Reagents for Organic Synthesis; Springer-Verlag: New York, 1983; p 273.
2. Larson, G. L. In The Chemistry of Organosilicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley Interscience; New York, 1989; p 763.
3. Fleming, I. Organic Silicon Chemistry in Comprehensive Organic Chemistry; Barton, O.; Ollis, W. D., Eds.; Pergamon Press: New York, 1979; Vol. 3, p 541.
4. Olah, G. A.; Prakash, G. K. S.; Krishnamurti, R. Adv. Silicon Chem. 1991, 1, 1.
5. Emde, H.; Domsch, D.; Feger, H.; Frick, U.; Götz, A.; Hergott, H. H.; Hofmann, K.; Kober, W.; Krägeloh, K.; Oesterle, T.; Steppen, W.; West, W.; Simchen, G. Synthesis 1982, 1.
6. + rather than silicenium ion, silylenium ion, or silyl cation, thus following recent IUPAC recommendations. See: Nomenclature of Inorganic Chemistry; Leigh, G. J., Ed.; Blackwell: Oxford, U.K., 1990; p 106.
7. + in solution see: (a) Lambert, J. B.; Kania, L.; Zhang, S. Chem. Rev. 1995, 95, 1191. (b) Chojnowski, J.; Stanczyk W.; Adv. Organomet. Chem. 1990, 30, 243, (c) Chojnowski, J.; Stanczyk W.; Main Group Chem. News 1994, 2, 6. (d) Lickiss, P. D. J. Chem. Soc., Dalton Trans. 1992, 1333.
8. + in solution see: (a) Lambert, J. B.; Kania, L.; Zhang, S. Chem. Rev. 1995, 95, 1191. (b) Chojnowski, J.; Stanczyk W.; Adv. Organomet. Chem. 1990, 30, 243, (c) Chojnowski, J.; Stanczyk W.; Main Group Chem. News 1994, 2, 6. (d) Lickiss, P. D. J. Chem. Soc., Dalton Trans. 1992, 1333.
9. + in solution see: (a) Lambert, J. B.; Kania, L.; Zhang, S. Chem. Rev. 1995, 95, 1191. (b) Chojnowski, J.; Stanczyk W.; Adv. Organomet. Chem. 1990, 30, 243, (c) Chojnowski, J.; Stanczyk W.; Main Group Chem. News 1994, 2, 6. (d) Lickiss, P. D. J. Chem. Soc., Dalton Trans. 1992, 1333.
10. + in solution see: (a) Lambert, J. B.; Kania, L.; Zhang, S. Chem. Rev. 1995, 95, 1191. (b) Chojnowski, J.; Stanczyk W.; Adv. Organomet. Chem. 1990, 30, 243, (c) Chojnowski, J.; Stanczyk W.; Main Group Chem. News 1994, 2, 6. (d) Lickiss, P. D. J. Chem. Soc., Dalton Trans. 1992, 1333.
11. (a) Lambert, J. B.; Schulz, W. J. J. J. Am. Chem. Soc. 1983, 105, 1671.
12. (b) Lambert, J. B.; McConnell, J. A.; Schulz, W. J. J. J. Am. Chem. Soc. 1986, 108, 2482.
13. (c) Lambert, J. B.; Schilf, W. J. Am. Chem. Soc. 1988, 110, 6364.
14. (d) Lambert, J. B.; Schulz, W. J. J.; McConnell, J. A.; Schilf, W. J. Am. Chem. Soc. 1988, 110, 2201.
15. (e) Lambert, J. B.; Kania, L.; Schilf, W.; McConnell, J. A. Organometallics 1991, 10, 2578.
16. (f) Lambert, J. B.; Zhang, S. J. Chem. Soc., Chem. Commun. 1993, 383.
17. (g) Lambert, J. B.; Zhang, S.; Stern, C. L.; Huffman, J. C. Science 1993, 260, 1917.
18. (h) Lambert, J. B.; Zhang, S.; Ciro, S. M. Organometallics 1994, 13, 2430.
19. (i) Lambert, J. B.; Zhang, S. Science, 1994, 263, 984.
20. (a) Olah, G. A.; Heiliger, L.; Li, X. Y.; Prakash, G. K. S. J. Am. Chem. Soc. 1990, 112, 5991.
21. (b) Prakash, G. K. S.; Keyaniyan, S.; Aniszfeld, R.; Heiliger, L.; Olah, G. A.; Stevens, R. C.; Choi, H. K.; Bau, R. J. Am. Chem. Soc. 1987, 109, 5123.
22. (c) Olah, G. A.; Rasul, G.; Heiliger, L.; Bausch, J.; Prakash, G. K. S. J. Am. Chem. Soc. 1992, 114, 7737.
23. (d) Olah, G. A.; Rasul, G.; Li, X.; Buchholz, H. A.; Sandford, G.; Prakash, G. K. S. Science, 1994, 263, 983.
24. (e) Olah, G. A.; Rasul, G.; Buchholz, H. A.; Li, X.-Y.; Prakash, G. K. S. Bull. Soc. Chim. Fr. 1995, 132, 569.
25. (f) Olah, G. A.; Li, X.-Y.; Rasul, G.; Prakash, G. K. S. J. Am. Chem. Soc. 1995, 117, 8962.
26. (a) Olsson, L.; Ottosson, C.-H.; Cremer, D. J. Am. Chem. Soc. 1995, 117, 7460.
27. (b) Olsson, L.; Cremer, D. Chem. Phvs. Lett. 1993, 215, 433.
28. (a) Schleyer, P. v. R.; Buzek, P.; Müller, T.; Apeloig, Y.; Siehl, H.-U. Angew. Chem. 1993, 105, 1558.
29. (b) Mearker, C.; Kapp, J.; Schleyer, P. v. R. Organosilicon Chemistry; Auner, N., Weis, J., Eds.; VCH (Weinheim): Weinheim, Germany, 1996; Vol. II, p 329.
30. Pauling, L. Science 1994, 263, 983.
31. (a) Reed, C. A.; Xie, Z. Science, 1994, 263, 985.
32. (b) Xie, Z.; Bau, R.; Reed, C. A. J Chem. Soc., Chem. Commun. 1994, 2519.
33. (c) Reed, C. A.; Xie, Z.; Bau, R.; Benesi, A. Science 1993, 262, 402.
34. (d) Xie, Z.; Liston, D. J.; Jelinek, T.; Mitro, V.; Bau, R.; Reed, C. A. J. Chem. Soc., Chem. Commun. 1993, 384.
35. (e) Xie, Z.; Bau, R.; Benesi, A.; Reed, C. A. Organometallics 1995, 14, 3933.
36. (a) Bassindale, A. R.; Jiang, S. J. Organomet. Chem. 1993, 446, C3.
37. (b) Bassindale, A. R.; Stout, T. J. Organomet. Chem. 1984, 271, C1.
38. Bassindale, A. R.; Stout, T. Tetrahedron Lett. 1985, 26, 3403.
39. (a) Bassindale, A. R.; Stout, T. J. Chem. Soc., Perkin Trans. 2 1986, 221.
40. (b) Bassindale, A. R.; Stout, T. J. Chem. Soc., Chem. Commun. 1984, 1387.
41. Bassindale, A. R.; Stout, T. J. Organomet. Chem. 1982, 238, C41.
42. Blake, A. J.; Cradock, S.; Ebsworth, E. A. V.; Franklin, K. C. Angew. Chem., Int. Ed. Engl. 1990, 29, 76.
43. Kira, M.; Hino, T.; Sakurai, H. J. Am. Chem. Soc. 1992, 114, 6697.
44. (a) Kira, M.; Hino, T.; Sakurai, H. Chem. Lett. 1993, 153.
45. (b) Bahr, S.; Boudjouk, P. J. Am. Chem. Soc 1993, 115, 4514.
46. Hensen, K.; Zengerly, T.; Pickel, P.; Klebe, G. Angew. Chem. 1983, 95, 739.
47. Hensen, K.; Zengerly, T.; Müller, T.; Pickel, P. Z. Anorg. Allg. Chem. 1988, 558, 21.
48. + in the gas phase see: Schwarz, H. In The Chemistry of Organic Silicon Compounds, Patai, S., Rappoport, Z., Eds.; Wiley Interscience: New York, 1989; p 445.
49. Li, X.; Stone, J. A. Int. J. Mass Spectrom. Ion Processes 1990, 101, 149.
50. (a) Wojnytiak, A. C. M.; Stone, J. A. Int. J. Mass Spectrom. Ion Processes 1986, 74, 59.
51. (b) Stone, J. A.; Wojtyniak, A. C. M.; Wytenburg, W. Can. J. Chem. 1986, 64, 575.
52. (a) Cacace, F.; Crestoni, M. A.; Fomarini, S. Int. J. Mass Spectrom. Ion Processes 1988, 84, 17.
53. (b) Stone, J. M.; Stone, J. A. Int. J. Mass Spectrom. Ion Processes 1991, 109, 247.
54. (c) Cacace, F.; Attina, M.; Fornarini, S. Angew. Chem. 1995, 107, 754.
55. Chuit, C.; Corriu, R. J. P.; Reye, C.; Young, J. C. Chem. Rev. 1993, 93, 1371.
56. (a) Cremer, D.; Olsson, L.; Reichel, F.; Kraka, E. Isr. J. Chem. 1993, 33, 369.
57. (b) Cremer, D.; Reichel, F.; Kraka, E. J. Am. Chem. Soc. 1991, 113, 9459.
58. (c) Svensson, P.; Reichel, F.; Ahlberg, P.; Cremer, D. J. Chem. Soc., Perkin Trans. 2 1991, 1463.
59. (d) Cremer, D.; Svensson, P.; Kraka, E.; Ahlberg, P. J. Am. Chem. Soc. 1993, 115, 7445.
60. (e) Sieber, S.; Schleyer, P. v. R.; Otto, A. H.; Gauss, J.; Reichel, F.; Cremer, D. J. Phys. Org. Chem. 1993, 6, 445.
61. (f) Szabo, K.; Kraka, E.; Cremer, D. J. Org. Chem. To be published.
62. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
63. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
64. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
65. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
66. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
67. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
68. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
69. See, e.g.: (a) Hnyk, D.; Vajda, E.; Buehl, M.; Schleyer, P. v. R. Inorg. Chem. 1992, 31, 2464. (b) Buehl, M.; Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 477. (c) Buehl, M.; Schleyer, P. v. R.; McKee, M. L. Heteroat. Chem. 1991, 2, 499. (d) Buehl, M.; Schleyer, P. v. R. Angew. Chem. 1990, 102, 962. (e) Schleyer, P. v. R.; Buehl, M.; Fleischer, U.; Koch, W. Inorg. Chem. 1990, 29, 153. (f) Schleyer, P. v. R.; Koch, W.; Liu, B.; Fleischer, U. J. Chem. Soc., Chem. Commun. 1989, 1098. (g) Bremer, M.; Schoetz, K.; Schleyer, P. v. R.; Fleischer, U.; Schindler, M.; Kutzelnigg, W.; Koch, W.; Pulay, P. Angew. Chem. 1989, 101, 1063. (h) Bühl, M.; Steinke, T.; Schleyer, P.v.R.; Boese, R. Angew. Chem., Int. Ed. Engl. 1991, 30, 1160.
70. Recent developments on large and weakly coordinating anions have been summarized by: Strauss, S. H. Chem. Rev. 1993, 93, 927.
71. (a) Gutman, V. Coord. Chem. Rev. 1976, 18, 225.
72. (b) Reichardt, C. Solvents and Solvent Effects in Organic Chemistry; VCH (Weinheim): Weinheim, Germany, 1988.
73. (c) Hückel, E. Z. Phys. Chem. 1940, 186, 129.
74. (a) Muller, N.; Pritchard, D. E. J. Chem. Phys. 1959, 31, 1471.
75. (b) Frei, K.; Bernstein, H. J. J. Chem. Phys. 1963, 38, 1216.
76. (a) Brook, A. G.; Abdesaken, F.; Gutekunst, G.; Plavac, N. Organometallics 1982, 1, 994.
77. See also: (b) Kovacek, D.; Maksic, Z. B.; Elbel, S.; Kudnig, J. J. Mol. Struct. (THEOCHEM) 1994, 304, 247.
78. A clear description of the reduced tendency of Si to form hybrid orbitals can be found in: (c) Kutzelnigg, W. Angew Chem., Int. Ed. Engl. 1984, 23, 272.
79. Chojnowski, J.; Cypryk, M.; Michalski, J. J. Organomet. Chem. 1978, 161, C31.
80. Bassindale, A. R.; Stout, T.; Taylor, P. G. J. Chem. Soc., Perkin Trans. 2 1986, 227.
81. (a) Lindman, B.; Forsén, S. NMR, Basic Principles and Progress; Springer Berlin, 1976; Vol. 12.
82. (b) Lindman, B.; Forsén, S. NMR and the Periodic Table; Harris, R. K., Mann, B. E., Eds.; Academic Press: London, 1978; p 421.
83. (a) Miertus, S.; Scrocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117.
84. (b) Bonaccorsi, R.; Cimiraglia, R.; Tomasi, J. J. Comp. Chem. 1983, 4. 567.
85. (c) Bonaccorsi, R.; Pala, P.; Tomais, J. J. Am. Chem. Soc. 1984, 106, 1945.
86. (d) Pascual-Ahuir, J. L.; Silla, E.; Tomasi, J.; Bonaccorsi, R. J. Comput. Chem. 1987, 8, 778.
87. Reichel, F.; Cremer, D. To be published.
88. (a) Kutzelnigg, W, Isr. J. Chem. 1980, 19, 193.
89. (b) Schindler, M.; Kutzelnigg, W. J. Chem. Phys. 1982, 76, 1919.
90. (c) Kutzelnigg, W.; Schindler, M.; Fleicher, U. NMR, Basic Principles and Progress: Springer: Berlin, 1989; Vol. 23.
91. (a) Cremer; D.; Kraka, E. Croat. Chem. Acta 1984, 57, 1259.
92. (b) Cremer, D.; Kraka, E. Angew. Chem., Int. Ed. Engl. 1984, 23, 62.
93. (c) Kraka, E.; Cremer, D. In Theoretical Models of the Chemical Bond, Part 2: The Concept of the Chemical Bond, Maksic, Z. B., Ed.; Springer: New York, 1990; p 453.
94. (d) Cremer, D. In Modelling of structure and properties of molecules; Maksic, Z. B., Ed.; Ellis Horwood; Chichester, England, 1988; p 125.
95. (e) Cremer, D.; Kraka, E. In Molecular Structure and Energetics, Structure and Reactivity; Liebman, J. F., Greenberg, A., Eds.; VCH Publishers: Deerfield Beach, FL, 1988; Vol. 7, p 65.
96. (f) Cremer, D. Tetrahedron 1988, 44, 7427.
97. Shieldrick, W. S. In The Chemistry of Organosilicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley Interscience: New York, 1989; p 227.
98. Schmidt, M. W.; Windus, T. L.; Gordon, M. S. J. Am. Chem. Soc. 1995, 117, 7480.
99. Dauben, H. J.; Honnen, L. R.; Harmon, H. K. J. Org. Chem. 1960, 25, 1442.
100. (a) Chein, J. C. W.; Tsai, W. M.; Rausch, M. D. J. Am. Chem. Soc. 1991, 113, 8570.
101. (b) Massay, A. G.; Park, A. J. Organometallic Synthesis; King, B. B., Eisch, J. J., Eds.; Elsevier: New York, 1986; Vol. 3, p 461.
102. (c) Massay, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245.
103. Hariharan, P. C.; Pople, J. A. Theor. Chim. Acta 1973, 28, 213.
104. Ottosson. C.-H.; Cremer, D. To be published.
105. Gauss, J.; Kraka, E.; Reichel, F.; Olsson, L.; He, Z.; Konkoli, Z.; Cremer, D. COLOGNE94; University of Göteborg, Sweden, 1994.
106. Frisch, M. J.; Head-Gordon, M.; Trucks, G. W.; Foresman, J. B.; Schlegel, H. B.; Raghavachari, K.; Robb, M. A.; Binkley, J. S.; Gonzalez, C.; Defrees, D. J.; Fox, D. J.; Whiteside, R. A.; Seeger, R.; Melius, C. F.; Baker, J.; Martin, R. L.; Kahn, L. R.; Stewart, J. J. P.; Topiol, S.; Pople, J. A., Gaussian 92, Gaussian Inc.: Pittsburgh, PA, 1992.
107. Olsson, L.; Cremer, D. To be published.