Paramagnetic Deshielding Effects by Aryl Groups of Triaryl-9-thioxanthenylphosphonium Perchlorate

삼아릴-9-티오크잔테닐포스포니움 과염소산염의 아릴기에 의한 상자기성 벗김 효과

  • Kwang Hyun Ahn (Department of Chemistry, College of Natural Science, Seoul National University) ;
  • Kyong Tae Kim (Department of Chemistry, College of Natural Science, Seoul National University)
  • 안광현 (서울대학교 자연과학대학 화학과) ;
  • 김경태 (서울대학교 자연과학대학 화학과)
  • Published : 1981.06.30

Abstract

In contrast with pmr (only multiplets at ${\delta}6.6$∼7.8 ppm) spectrum of triphenyl-9-thioxanthenylphosphonium perchlorate and tri-o-methoxyphenyl-9-thioxanthenylphosphonium perchlorate, tri-n-butyl-9-thioxanthenylphosphonium perchlorate and tribenzyl-9-thioxanthenylphosphonium perchlorate showed a doublet at ${\delta}5.58$ and 5.70ppm, respectively, assigned to a methine proton. This value is slightly larger than the corresponding values (${\delta}5.05$~5.30) of 9-arylthioxanthenes but clearly differentiated from those of aromatic protons. This result implys that the downfield shift of a methine proton of triaryl-9-thioxanthenylphosphonium perchlorate is not due to inductive effects of an electron deficient phosphorus atom but paramagnetic deshielding effects by three aryl groups on phosphorus.

삼페닐-9-티오크잔텐닐포스포니움 과염소산염과 삼-오르토-메톡시페닐-9-티오크잔텐닐포스포니움 과염소산염과는 대조적으로 삼-n-부틸-9-티오크잔텐닐포스포니움 과염소산염과 삼벤질-9-티오크잔텐닐포스포니움 과염소산염은 각각 ${\delta}5.58$ppm과 ${\delta}5.70$ ppm 에서 methine 양성자에 해당하는 이중상을 보여주었다. 이 값은 9-아릴티오크잔틴의 상응값 (${\delta}5.05$~5.30)보다 다소 큰 값이나 방향족화합물의 양성자의 값과는 분명히 차이가 난다. 이 결과는 삼아릴-9-티오크잔텔닐포스포니움 과염소산염의 methine 양성자가 낮은 장으로 이동한 원인이 전자가 부족한 인원자에 의한 유발 효과때문이 아니라 인에 결합된 세개의 아릴기의 상자기성 벗김 효과에 의한 것임을 의미한다.

Keywords

References

  1. Chem. Ber. v.91 L. Hornes;B. Nippe
  2. Organic Phosphorus Compounds v.2 P. Beck;G. M. Kosolapoff(ed.);L. Maier(ed.)
  3. J. Korean Chem. Soc. v.24 K. Kim
  4. MS thesis, S. N. U. Nak-Chul Jeong
  5. Tetrahedron Letts. W. Rundell;K. Scheffer
  6. Chem. Ber. v.94 O. Neunhoeffer;L. Lamza
  7. J. Chem. Soc. R. C. Hinton;F. G. Mann
  8. Inorg. Syn. v.8 L. R. Ocone;C. W. Schaumann;B. P. Block
  9. Application of Nuclear Magnetic Resonance Spectroscopy in Organic Chemistry(2nd Ed.) L. M. Jackman;S. Sternhell
  10. Progress in Nuclear Magnetic Resonance Spectroscopy v.1 G. Mavel;J. W. Emsley(ed.);J. Freeney(ed.);L. H. Sutcliffe(ed.)
  11. Compt. Rend. v.252 G. Mavel;G. Martin
  12. Tetrahedron v.20 J. B. Hendrickson;M. L. Maddox;J. J. Sims;H. D. Kaesz
  13. Spectrochimica Acta. v.21 A. G. Massey;E. W. Randall;D. Shaw
  14. J. Chim. Phys. v.62 G. Mavel;G. Martin
  15. Chem. Rev. v.63 P. R. Wells
  16. J. Organometal. Chem. v.3 C. E. Griffin;M. Gordon
  17. J. Org. Chem. v.29 E. E. Schweizer;R. D. Bach
  18. Chem. Ber. v.102 F. Cassar;W. Balzer
  19. J. Org. Chem. v.28 H. O. House;H. Babad
  20. J. Org. Chem. v.29 E. A. LaLancette
  21. J. Chem. Phys. v.41 M. Gordon;C. E. Griffin
  22. J. Phys. Chem. v.70 S. O. Grim;W. McFarlane;E. F. Davidoff;T. J. Marks