Photochemistry of Potassium Ferrocyanide and its Reaction with Uridine 5′-monophosphate in Aqueous Solution under Ultraviolet Irradiation  

紫外光照下亚铁氰化钾的光化学性质及其与5'-尿嘧啶核苷酸的反应

作　　者：Song-qiu Yang Yan Zhang Yan-ni Wang 羊送球;张岩;王艳妮(中国科学院大连化学物理研究所,分子反应动力学国家重点实验室,大连116023;大连海事大学理学院,大连116023)

机构地区：[1]State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [2]School of Science,Dalian Maritime University,Dalian 116026,China

出　　处：《Chinese Journal of Chemical Physics》2022年第5期764-773,I0014-I0022,I0011,I0012,共21页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China(No.21873100 and No.21773226);the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics in Dalian Institute of Chemical Physics,Chinese Academy of Sciences。

摘　　要：The photochemical reaction of potassium ferrocyanide(K_(4)Fe(CN)_(6))exhibits excitation wavelength dependence and non-Kasha rule behavior.In this study,the excited-state dynamics of K_(4)Fe(CN)_(6) were studied by transient absorption spectroscopy.Excited state electron detachment(ESED)and photoaquation reactions were clarified by comparing the results of 260,320,340,and 350 nm excitations.ESED is the path to generate a hydrated electron(e^(−)_(aq)).ESED energy barrier varies with the excited state,and it occurs even at the first singlet excited state(^(1)T_(1g)).The ^(1)T_(1g) state shows∼0.2 ps lifetime and converts into triplet[Fe(CN)_(6)]4−by intersystem crossing.Subsequently,3Fe(CN)_(5)]^(3-)appears after one CN−ligand is ejected.In sequence,H2O attacksFe(CN)_(5)]^(3-)to generate[Fe(CN)_(5)H_(2)O]^(3−)with a time constant of approximately 20 ps.The ^(1)T_(1g) state and e−aq exhibit strong reducing power.The addition of uridine 5′-monophosphate(UMP)to the K_(4)Fe(CN)_(6) solution decrease the yield of e−aq and reduce the lifetimes of the e−aq and ^(1)T_(1g) state.The obtained reaction rate constant of ^(1)T_(1g) state and UMP is 1.7×10^(14)(mol/L)^(−1)·s^(−1),and the e−aq attachment to UMP is∼8×10^(9)(mol/L)^(−1)·s^(−1).Our results indicate that the reductive damage of K_(4)Fe(CN)_(6) solution to nucleic acids under ultraviolet irradiation cannot be neglected.

关 键 词：Ultrafast spectroscopy Photoaquation Electron detachment Excited state dynamics Ferrous hexacyanides 

分 类 号：O621.25[理学—有机化学]