TRIPLET EXCITED STATES OF PYRIMIDINE NUCLEOSIDES AND NUCLEOTIDES

Abstract

Abstract— The triplet absorption spectra, lifetimes, extinction coefficients, e TT , and intersystem crossing quantum yields to the lowest triplet T 1 , ø T1 , of thymidine, thymidine monophosphate, uridine and uridine monophosphate, have been determined in various solvents at 300 K. The effect of H‐bonding on ø T1 , of these nucleosides and nucleotides and also of uracil has been determined and discussed. This effect allows, an ordering of l,3 n, π* and 1,3 π, π* states in protic and aprotic solvents.