摘 要
　　利用B3LYP/6-31G＊計算去質子的X-C6H4CH(CF3)2結構，由NBO分析所得到的最佳路易士結構顯示，苯基上有三個共軛雙鍵，以及由異丙基傳到苯基且定域化在對位碳上的未鍵結電子對LP(C6)。因此，關於穩定負電荷的研究，將著重於LP(C6)，以及連接在苯基和丙基之間π-電子(πC3-C12)的傳遞。
　
　　關於穩定X-C6H4C(CF3)2－上負電荷的能量，藉由苯基上反鍵結π-type BOs所貢獻的部份為156.42 kcal/mol，此比氟超共軛所貢獻的56.06 kcal/mol還要高。

　　在對位(C6)上以CCl3取代對於穩定負電荷的效力比CF3取代高，此為p(F)-π(benzene) interaction的影響。關於鹵素取代在對位上的E(2)穩定能大小，受到了鹵素陰電性和共振效應(+R donation)的影響。

　　X-C6H4C(CH3)2－的穩定度增加了，特別是X為拉電子基時，例如p-CN和p-CCl3。當X為p-CN和p-CCl3時，isodesmic reactions 的DEreaction值分別為-16.685和-15.528 kcal/mol。若X為p-N(CH3) 2時，DEreaction值為4.123 kcal/mol，此表示p-N(CH3) 2沒有產生穩定負電荷效力。利用理論計算所得的DEreaction值與其σcarbon acid值有相符的結果。

Abstract
　　The deprotonated X-C6H4CH(CF3)2 structures have been optimized by B3LYP/6-31G* calculations. The best Lewis structure obtained by NBO method is described by three conjugated double bonds with the lone-pair electrons localized at the phenyl carbon para to the propyl group denoted as LP(C6). Therefore, the stabilization of the negative charge has been investigated focused on LP(C6) and the two-center π-electrons connecting phenyl and propyl groups denoted as πC3-C12.

　　It was found that the stabilization energy contributed to the negative charge in X-C6H4C(CF3)2－ by the anti-bonding π-type BOs of the phenyl moiety is 156.42 kcal/mol, which is larger then the 56.06 kcal/mol contributed by the conventional F-hyperconjugation.

　　Substitution at the para position (C6) with CCl3 showed a higher stabilization effect to the negative charge than with CF3, due to there being p(F)-π(benzene) interaction. The E(2) stabilization energy due to the substitutions by halogen at para position is depend on both the electronegativity and mesomeric effects (+R donor) of the halogens.

　　X-C6H4C(CF3)2－ showed more stable, especially, when the X is electron withdrawing group, such as p-CN or p-CCl3. The △Ereaction of isodesmic reaction for X being p-CN and p-CCl3 are -16.685 and -15.528 kcal/mol, respectively. For X being p-N(CH3)2, the △Ereaction is 4.123 kcal/mol, indication that it has not effect in stabilization the negative charge. Theoretical calculation of △Ereaction showed a consistent result with σcarbon acid.

1.Klabunde, K. J. J. Am. Chem. Soc., 1972, 94,820
2.Roithova, J.; Exner, O. J. Phys. Org. Chem., 2001, 14, 752.
3.Exner, O.; Bohm, S. J. Org. Chem., 2002, 67, 6320.
4.Reed, A. E.; Schleyer, P. v. R. J. Am. Chem. Soc., 1987, 109, 7362.
5.Barbour, J. B.; Karty, J.M.; Bohm. S. J. Org. Chem., 2004, 69, 648.
6.Jones, M. Organic Chemistry, 2nd ed.; W. W. Norton Company Inc.: New York, 2000.
7.Mulliken, R. S. J. Phys. Chem., 1933, 1, 492; 1935, 3, 520; 1937, 7, 339.
8.Mo, Y.; Jiao, H.; Schleyer, P. v. R. J. Org. Chem., 2004, 69, 3493.
9.Carey, F. A.; Sundberg, R. J. Advanced Organic Chemistry, 4th ed.; Kluwer Academic/Plenum Publishers Press:New York, 2000.
10.Solomons, T. W. G. Organic Chemistry revised printing; Wiley, John ＆ Sons. Inc.: New York, 2000.
11.Holt, J.; Karty, J. M. J. Am. Chem. Soc., 2003, 125, 2797.
12.Brockway, L. O. J. Phys. Chem., 1937, 41, 185.
13.Roberts, J. D.; Webb, R. L.; McElhill, E. A. J. Am. Chem. Soc., 1950, 72, 408.
14.Andreades, S. J. Am. Chem. Soc., 1964, 86, 2003.
15.Radom, R.; Hoffmann, L.; Pople, J. A.; Schleyer, P. v. R.; Hehre, W. J.; Salem, L. J. Am. Chem. Soc., 1972, 94, 6221.
16.Schleyer, P. v. R.; Kos, A. J. Tetrahedron, 1983, 39, 1141.
17.Schneider, W. F.; Nance, B. I.; Wallington, T. J. J. Am. Chem. Soc., 1995, 117, 478.
18.黃士凌, 國立成功大學碩士論文, 2004.
19.Steinfeld, J. I.; Francisco, J. S.; Hase, W. L. Chemical Kinetics And Dynamics, 2nd ed.; Prentice-Hall, Inc.: New Jersey, 1999.
20.Huheey, J. E.; Keiter, E. A.; Keiter, R. L. Inorganic Chemistry fourth edition; Harper Collins College Publishers: New York, 1993.
21.Sheppard, W. A. J. Am. Chem. Soc., 1965, 87, 2410.
22.Huzinaga, S. Gaussian Basis Sets for Molecular Calculations; Elsevier: New York, 1984.
23.黃國棠, 國立成功大學碩士論文, 2004.
24.Hehre, W. J.; Radom, L.; Schleyer, P. V. R.; Pople, J. A. ab Initio Molecular Orbital Theory; Wiley, John ＆ Sons. Inc.: Canada, 1986.
25.Hohenberg, P.; Kohn, W. Phy. Rev. B, 1964, 136, 864.
26.Slater, J. C. Quantum Theory of Molecular and Solids. Vol. 4: The Self-Consistent Field for Molecular and Solids; McGraw-Hill: New York, 1974.
27.Kohn, W.; Sham, L. J. Phys. Rev. A, 1965, 140, 1133.
28.Becke, A. D. Phys. Rev. A, 1988, 38, 3098.
29.Perdew, J. P.; Wang, Y. Phys. Rev. B, 1992, 45, 13244.
30.Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B, 1988, 37, 785.
31.Reed, A. E.; Curtiss, L.; Weinhold, A. F. Chem. Rev., 1989, 88, 899.
32.林岱弘, 國立成功大學碩士論文, 2005.
33.Gaussian 98, Revision A.9,
M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, V. G. Zakrzewski, J. A. Montgomery, Jr., R. E. Stratmann, J. C. Burant, S. Dapprich, J. M. Millam, A. D. Daniels, K. N. Kudin, M. C. Strain, O. Farkas, J. Tomasi, V. Barone, M. Cossi, R. Cammi, B. Mennucci, C. Pomelli, C. Adamo, S. Clifford, J. Ochterski, G. A. Petersson, P. Y. Ayala, Q. Cui, K. Morokuma, D. K. Malick, A. D. Rabuck, K. Raghavachari, J. B. Foresman, J. Cioslowski, J. V. Ortiz, A. G. Baboul, B. B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. Gomperts, R. L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng, A. Nanayakkara, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen, M. W. Wong, J. L. Andres, C. Gonzalez, M. Head-Gordon, E. S. Replogle, and J. A. Pople, Gaussian, Inc., Pittsburgh PA, 1998.
34.DeTar, D. F. J. Org. Chem., 1995, 60, 7125.
35.Hehre, W. J.; Ditchfield, R.; Radom, L.; Pople, J. A. J. Am. Chem. Soc., 1970, 92, 4796.