Vibrational Mode Analysis of Isotope-Labeled Electronically Excited Riboflavinстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 11 ноября 2019 г.
Авторы:
Wolf Matthias M.N,
Herbert Zimmermann,
Rolf Diller,
Tatiana Domratcheva
Аннотация:Isotope-labeled riboflavin in DMSO was employed in conjunction with femtosecond time-resolved infrared vibrational spectroscopy and quantum chemical calculations to analyze and assign the electronically excited state vibrational modes of the isoalloxazine unit as a prototype for the cofactors in flavin binding blue-light receptors. Using the riboflavin 13C-analogues RF-2-13C and RF-4,10a-13C, the carbonyl vibrations, in particular, were studied. Various quantum chemical models were applied that take into account a polarizable environment or the impact of hydrogen bonds. The CIS quantum-chemistry method was successfully applied to describe the lowest singlet excited electronic state in riboflavin. The experimentally observed frequencies and isotope-shifts as well as their variability in the diverse model calculations are discussed. On these grounds, a consistent assignment of the electronic ground and excited state vibrations is presented.