Substituent and Solvent Effects on the Lifetimes of Hydrocarbon-Based Biradicals

摘要

Nanosecond transient absorption studies of the lifetimes tau of several substituted 1, n-diphenyl-1, n-diyls are reported in polar and non-polar solvents. A para-bromine substituent significantly shortens tau. Substitution of OH in the 1-position makes the lifetime highly solvent dependent. The substituent effect and the dependence of tau on biradical chain length is discussed in terms of spin-orbit coupling in the biradical. Keywords: biradicals; energy transfer; transient absorption; spin orbits; coupling.