Investigation of the linear and nonlinear optical response of edge-linked conjugated zinc porphyrin oligomers by optical spectroscopy and configuration interaction techniques

Publisher Website
Google Scholar
Abstract
We present a joint experimental and theoretical investigation of the linear and nonlinear optical response of butadiyne-linked zinc porphyrin oligomers. Efficient overlap between the chromophores leads to a large red-shift of the Q absorption band together with a splitting of the B band into two components when increasing the chain length from one to two repeating porphyrin units. Ultrafast pumb-probe measurements performed on these compounds show several well-defined features, associated with singlet excited state absorption. We also find clear evidence for the formation of longer-lived triplet excitons, resulting from very efficient singlet–triplet intersystem crossing processes. For the monomers, the assignment of the observed linear and photoinduced absorption features is supported by a Configuration Interaction description of the singlet and triplet excited states. In the case of the porphyrin dimer, agreement with the experimental results can only be obtained by considering a sizable cumulenic contribution in the excited-state geometry used as input for the CI calculations. The potential of porphyrin systems for Reverse Saturable Absorption and Nonlinear Optics is emphasized.

This publication has 48 references indexed in Scilit: