Excited-state of multiple proton transfer via molecular wire facilitated by hydrogen bond strengthening in excited state
Abstract：As the most common reactions in nature,Proton transfer(PT) is one of the most important subjects in dynamic research.In particular,the novel excited-state multiple proton transfer(ESMPT) occurred along hydrogen-bonded wire illustrates a good prospect of application in the aspects of green fluorescent protein.In this work,we systematically study the dynamic behavior of ESMPT by using density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods.Based on the excited-state hydrogen bond strengthening theory established by Zhao Guang-Jiu and Han Ke-Li,we obtained some novel mechanism for the excited-state proton transfer(ESPT) reaction of 6-hydroxyquinoline(6HQ) and its cationic form 6HQc:(1) Excited-state hydrogen bond strengthening and weakening could exist simultaneously in one hydrogen-bonded complex,which dependent on the charge transfer upon photoexcitation.(2) Only the water cluster containing more than 3 water molecules could capture the proton in photoacid,while the single water molecule is incapable for this PT reaction.(3) The mechanism of ESMPT reaction is a complicated process,which might contain both the step-wise and concerted fashions.
Keywords：proton transferexcited statehydrogen bondphotoacid
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 317-323 )