대한화학회지 (Journal of the Korean Chemical Society)

  • 제30권1호
  • /
  • Pages.9-18
  • /
  • 1986
  • /
  • 1017-2548(pISSN)
  • /
  • 2234-8530(eISSN)
대한화학회 (Korean Chemical Society)
권호 표지

${\alpha}$-치환 아세톤의 궤도간 상호작용과 형태에 관한 이론적 연구

Theoretical Studies on Orbital Interactions and Conformation of ${\alpha}$-Substituted Acetones

  • 이익춘 (인하대학교 이과대학 화학과) ;
  • 양기열 (인하대학교 이과대학 화학과) ;
  • 김왕기 (전남대학교 사대 화학교육과) ;
  • 공병후 (충북대학교 사대 과학교육과) ;
  • 이병춘 (충북대학교 사대 과학교육과)
  • Ikchoon Lee (Department of Chemistry, Inha University) ;
  • Kiyull Yang (Department of Chemistry, Inha University) ;
  • Wang Ki Kim (Department of Chemical Education, Chonnam National University) ;
  • Byung Hoo Kong (Department of Science Education, Chungbuk National University) ;
  • Byung Choon Lee (Department of Science Education, Chungbuk National University)
  • 발행 : 1986.02.20
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

${\alpha}$-치환아세톤($CH_2XCOCH_3$, X = F, Cl, OH, SH 및 $NH_2$)의 상대적 형태안정성을 결정하기 위하여 MNDO 및 STO-3G계산을 수행하였다. 계산결과 cis형이 더 안정한 F 및 $NH_2$ 치환 아세톤의 경우를 제외하고 모두 gauche형에 해당하는 형태이성체가 안정함을 밝혔다. gauche형에 대한 안정성은 ${\sigma}_{cx}$와 ${\pi}_{co}^*$궤도간의 two-orbital-two-electron상호작용에 의한 것으로 생각되며 이것은 gauche형에서의 vicinal overlap이 상당히 크다는 점과 두 궤도간의 에너지간격이 작다는 점에서 비롯된다. 아울러 이러한 에너지간격의 좁힘현상은 ${\sigma}_{cx}^*$-${\pi}_{co}^*$궤도간의 hyperconjugation상호작용 때문에 ${\pi}_{co}^*$궤도가 낮아졌기 때문이다. 또한 gauche형에서의 여러가지 ${\sigma}-{\pi}$상호작용들은 X가 Cl 및 SH인 3주기 원자들에게 더 강함을 보였다. 한편 질소원자의 비결합궤도함수 $n_N$과 인접 C-C ${\sigma}$결합의 상호작용은 cis일 경우 보다 trans배향일 경우에 더 강하였다.

MNDO and STO-3G calculations were performed to determine relative stabilities of rotamers for ${\alpha}$-substituted acetones, $CH_2XCOCH_3$, X = F, Cl, OH, SH, and $NH_2$. It was found that rotamers corresponding to gauche forms are preferred for all the ${\alpha}$-substituents except for X = F and NH$_2$, for which the cis forms were the preferred ones. The stability of gauche form was dictated by the stabilizing two-orbital-two-electron interaction ${\sigma}_{cx}$-${\pi}_{co}^*$, operating uniquely in the gauche form due to the substantial vicinal overlap and energy gap narrowing between ${\sigma}_{cx}$ and ${\pi}_{co}^*$ orbitals. The energy gap narrowing was caused by the lowering of ${\pi}_{co}^*$ level due to the hyperconjugative ${\sigma}_{cx}^*$-${\pi}_{co}^*$ interactions; the red shift in the n-${\pi}^*$ transition was another effect of the relatively large ${\sigma}_{cx}^*$-${\pi}_{co}^*$ splitting. Various ${\sigma}-{\pi}$ interactions in the gauche form were found to be stronger in the third-row hetero atom system, X = Cl and SH. Interactions between nonbonding orbital on N, $n_N$ and vicinal C-C ${\sigma}$ bond were shown to be stronger in the trans than in the cis orientation.

키워드

참고문헌

  1. J. Chem. Soc. L.J. Bellany;R.L. Williams
  2. J. Chem. Phys. v.47 G.A. Crowder;B.R. Cook
  3. J. Chem. Phys. v.21 S.I. Mizushima;T. Shimanouchi;T. Miyaxama;I. Ichishima;K. Kuratani
  4. J. Chem. Phys. v.52 E. Saegebarth;L.C. Krisher
  5. Spectrochim. Acta v.25A K.Yates;S.L. Klemento;I.G. Csizmadia
  6. J. Chem. Soc. Perkin Trans. II S.A. Guerrero;J. R-T. Barros;B. Wladislaw;R. Ritter;P.R.Olivato
  7. J. Chem. Soc. Perkin Trans. II P.R. Olivato;S.A. Guerrero;A. Modelli;G. Granozzi;D. Jones;G. Distefarro
  8. J. Am. Chem. Soc. v.88 N.L. Allinger;J.C. Tai;M.A. Miller
  9. J. Am. Chem. Soc. v.88 J.C. Tai;N.L. Allinger
  10. J. Am. Chem. Soc. v.99 M.J.S. Dewar;W. Thiel
  11. J. Chem. Phys. v.51 W.J. Hehre;R.F.Stewart; J.A. Pople
  12. J. Chem. Phys. v.54 R. Ditchfield;W.J. Hehre;J.A. Pople
  13. Bull. Korean Chem. Soc. v.1;4 I. Lee
  14. Bull. Korean Chem. Soc. v.1 I. Lee;K.B. Rhyu
  15. J. Korean Chem. Soc. v.24 I. Lee;B-S. Lee
  16. J. Am. Chem. Soc. v.101 T.K. Brunck;F. Weinhold
  17. J. Am. Chem. Soc. v.95 N.D. Epiotis
  18. J. Am. Chem. Soc. v.106 M.J.S. Dewar
  19. Tetrahedron I. Lee;K. Yang;H.S. Kim
  20. J.Am. Chem. Soc. v.103 K. Raghavachari;R.A. Whiteside;J.A. Pople;P.V.R. Schleyer
  21. Topics in Current Chemistry 70 Structural Theory of Organic Chemistry N.D. Epiotis;W.R. Cherry;S.Shaik;R.Yates;F. Bernardi
  22. Orbital Interactions in Chemistry T.A. Albright;J.K. Burdett;M.H. Whangbo
  23. Bull. Korean Chem. Soc. v.6 B.H. Kong;B.C. Lee;I. Lee;K.Yang
  24. J. Chem. Soc. M.J. Aroney;R.J.W.Le Fevre;A.N. Singh
  25. J. Chem. Phys. v.42 E. Hirota
  26. Discus. Faraday Soc. v.34 A.A. Bothner-By; H. Gunther
  27. J. Am. Chem. Soc. v.98 F. Weinhold;T.K. Brunk
  28. J. Am. Chem. Soc. v.101 T.K. Brunck;F. Weinhold
  29. J. Am. Chem. Soc. v.99 N.D. Epiotis;R.L.Yates;J-R. Larson;C.R. Kirmaier;F.Bernardi
  30. Rev. Mod. Phys. v.23 C.C.J. Roothaan
  31. Acc. Chem. Res. v.4;1 R. Hoffmann
  32. J. Am. Chem. Soc. v.90 R. Hoffmann;A. Imamura;W.J. Hehre
  33. Tetrahedron Letters P. Bischof;J.A. Hashmall;E. Heilbronner;V. Hornung
  34. Tetrahedron v.39 I. Lee
  35. Bull. Korean Chem. Soc. v.3 I. Lee
  36. Bull. Inst. Basic Sci.(Inha Univ.) v.4 I. Lee
  37. J. Korean Chem. Soc. v.27 I. Lee; C.K. Sohn;W.K. Kim
  38. J. Korean Chem. Soc. v.29 I. Lee;H.S. Kim;J-H. Choi
  39. J.Chem. Soc. Perkin II C.C. Levin;R. Hoffmann