Electronic Structure of Flavins. Inclusion of Methyl Groups in Molecular Orbital Treatments of Flavins

  • Published : 1972.06.30

Abstract

Various MO methods with differing degrees of sophistication are shown to yield qualitatively consistent results for methyl isoalloxazins. However, with crude methods such as the HMO and ${\omega}$-technique, the choice of Coulomb and resonance integralsis critical, in contrast with simpler molecular systems. The empirical value of ${\omega}$=0.5 appears to be more reasonable than 1.4. Methyl groups in these flaving are best treated by the group orbital approximation. The pseudo-heteroatom approximation overestimates methyl hyperconfiguration with the Pariser-Parrpole SCR MO method. siglet ${\pi}{\rightarrow}{\pi}^*$ transition energies are calculated by the P-P-P method and agree reasonably with the experimental values. 2- and 4-Thioisoalloxazine analogs are also treated. Reactivity indices of the flavin molecule are presented, includeing superdelocalizability. frontier orbital and radical densities. Various aspects of the applications of these indices of the methyl groups on dipolemoments, inozation potentialsm elctron affinities, and spectra are decribed in detail.

Keywords

References

  1. Proc. Natl. Acad. Sci. U. S. v.45 B. Pullman;A. Pullman
  2. Bull. Math. Biophys. v.23 G. Karreman
  3. Internatl. J. Quantum Chem. v.3 P.S.Song
  4. Biopolymers Symp. No. 1 B. B. Crabe
  5. Ark. Fysik v.17 B. Grabe
  6. Biochim. Biophys. Acta v.109 J.L.Fox;K. Nishimoto;L.S.Forster
  7. Biochim. Biophys. Acta v.136 J.L.Fox;S.P. Laberge;K. Nishimoto;L. S. Forster
  8. J. Amer. Chem. Soc. v.63 R.S. Mulliken;C.A. Rieke;W.G. Brown
  9. J. Amer. Chem. Soc. v.72 F.A.Matsen
  10. Molecular Orbital Theory for Organic Chemists A. Streitwieser, Jr.
  11. J. Amer. Chem. Soc. v.57 G. W. Wheland;L. Pauling
  12. J. Chem. Phys. v.18 H. C. Longuet-Higgins
  13. Quart. Rev. (London) v.21 G. R. Penzer;G. K. Radda
  14. J. Org. Chem. v.30 F.J. Bullock;O. Jardetzky
  15. Angew. Chem. v.77 P. Hemmerich;C. Veeger;H.C.S. Wood
  16. J. Gen. Chem. (U.S.S.R.) v.28 V.M. Berozovskii;E.P.Rodinova
  17. Helv. Chim. Acta v.47 K.H.Dudley;A. Ehrenberg;P. Hemmerich;F. Muller
  18. J. Heterocyclic Chem. v.4 D.B.McCormick
  19. The Enzymes v.II H. Beinert;P.D.Boyer(ed.);H. Lardy(ed.);K.Myrback(ed.)
  20. Electronic Aspects of Biochemistry A. Ehrenberg;B. Pullnam(ed.)
  21. Flavins and Flavoproteins A. Ehrenberg;L.E.G. Erikseon;F. Muller;E. C. Slater(ed.);C. Veeger(ed.)
  22. J. Phys. Chem. v.72 P. S. Song
  23. Flavins and Flavoproteins P.Hemmerich
  24. Quantum Biochemistry, Interscience B.Pullman;A. Pullman
  25. J. Chem. Phys. v.21 R.Pariser;R.G.Parr
  26. Trans. Farad. Soc. v.49 J.A.Pople
  27. Internarl. J. Quantum Chem. v.1 P.S.Song;T.A. Moore
  28. Arch. Biochem. Biophys. v.122 J.A.Anderson;P.S.Song
  29. Introduction to Quiantum Chemistry T.Yonezawa;C. Nagata;H.Kato;A. Imamura;K. Morokuma
  30. Molec. Phys. v.11 H.Looyenga
  31. Advances in Quantum Chemistry v.3 K. Ohno;P.-O. Lowdin(ed.)
  32. Advances in Quantum chemistry v.2 I.Fischer-Hjalmars
  33. Molecular Orbitals in Chemistry, Physics, and Biology I. Fischer-Hjalmars;P.-O. Lowdin(ed.);B. Pullman(ed.)
  34. J. Amer. Chem. Soc. v.89 P.S.Song;W.E.Kurtin
  35. Bull. Chem. Soc. Japan v.40 A.Imamura;H.Fujita;C.Nagata
  36. Molec. Phys. v.11 P. Knowlton;W.R.Carper
  37. Theoret. Chim. Acta v.7 A. Denis;A. Pullman
  38. Photochem. Photobiol. v.7 P.S.Song
  39. Flavins and Flavoproteins P. Kierkegaard;Norrestam;P.-E. Werner;I. Csoregh;M.von Glehn;R.Karlsson;M.Leijonmarck;O.Ronnquist;B. Stensland;O. Tillberg;L. Torbjornsson;H.Kamin(ed.)
  40. Bull. Chim. Soc. v.15 A. Pullman;J. Metzger
  41. Osaka Daigagu Igaku Z. v.8 M.Mizutani
  42. Quantum Chemistry, Interscience R. Daudel;R. Lefebvre;C. Moser
  43. Physica. v.1 T.Koopmans
  44. Theoret. Chim. Acta v.9 R.L.Flurry, Jr.
  45. Bond Energies, Ionization Potentials and Electron Affinities V.I.Vedeneyev;L.V. Gurvich;V.N.Kondrat`yev;V.A.Medvedev;Ye.L.Frankevich
  46. Rev. Mod. Phys. v.32 B. Pullnam;A. Pullman
  47. Biochemistry v.5 A. H. Neims;D. C. Deluca;L. Hellerman
  48. J. Amer. Chem. Soc. v.92 L. E. Brown;G. A. Hamilton
  49. Bull Chem. Soc. Japan v.34 K. Fukui;K. Morokuma;T. Yonezawa
  50. J. Amer. Chem. Soc. v.90 L. Salem
  51. Nature v.213 P. Hemmerich;V.Massey;G.Weber
  52. P.S.Song
  53. Photochem. Photobiol. v.7 W.E.Kurtin;P.S. Song
  54. Acta Chem. Scand. v.21 B.Roos
  55. Tetrahedron Letters No. 15 B. Tinland
  56. Molecular Biophysics B. Pullman;B. Pullman(ed.);M. Weissbluth(ed.)