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A theoretical consideration of the spectral properties of flavin tautomers and imino flavins
Author(s) -
Song PillSoon
Publication year - 1968
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560020405
Subject(s) - tautomer , flavin group , chemistry , bathochromic shift , computational chemistry , schiff base , keto–enol tautomerism , molecule , photochemistry , stereochemistry , organic chemistry , fluorescence , quantum mechanics , physics , enzyme
The Hückel MO and semiempirical SCF – ASMO – CI methods have been employed to calculate transition energies of seven possible flavin tautomers and two imino flavins (Schiff bases). The calculated spectral transition energies indicate that the tautomerism and Schiff base formation are accompanied by a bathochromic shift with reference to the absorption spectrum of riboflavin. This shift is especially pronounced in the case of the 4‐enol forms of the isoalloxazine molecule. The 4‐enolic tautomers also have lowest triplet levels well below the triplets of other tautomers. The significance of the results has been discussed.