The photochemical reaction of potassium ferrocyanide(K4Fe(CN)6)exhibits excita-tion wavelength dependence and non-Kasha rule behavior.In this study,the excited-state dynamics of K4Fe(CN)6 were studied by transient absorp-tion spectroscopy.Excited state electron detachment(ESED)and photoaquation reactions were clarified by comparing the results of 260,320,340,and 350 nm excita-tions.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(1T1g).The 1Tig state shows～0.2 ps lifetime and converts into triplet[Fe(CN)6]4-by intersystem crossing.Subsequently,3[Fe(CN)5]3-appears after one CN-ligand is ejected.In sequence,H2O attacks[Fe(CN)5]3-to generate[Fe(CN)5H2O]3-with a time constant of approximately 20 ps.The 1Tig state and e(aq-)exhibit strong reducing power.The addition of uridine 5'-monophosphate(UMP)to the K4Fe(CN)6 solution decrease the yield of e(aq-)and reduce the lifetimes of the e(aq-)and 1Tig state.The obtained reaction rate constant of 1Tig state and UMP is 1.7x1014(mol/L)-1·s-1,and the e(aq-)attachment to UMP is～8×109(mol/L)-1·s-1 Our results indicate that the reductive damage of K4Fe(CN)6 solution to nucleic acids under ultraviolet irradiation cannot be neglected.

Song-qiu Yang;Yan Zhang;Yan-ni Wang

State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;School of Science,Dalian Maritime University,Dalian 116026,China

化学物理学报（英文版）

[1]Song-qiu Yang;Yan Zhang;Yan-ni Wang-.Photochemistry of Potassium Ferrocyanide and its Reaction with Uridine 5'-monophosphate in Aqueous Solution under Ultraviolet Irradiation)[J].化学物理学报（英文版）,2022(05):764-773

Photochemistry,Ferrocyanide,ferrocyanide,Kasha,ESED,photoaquation,1T1g,1Tig,7x1014

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