DFT and TD-DFT calculations of axially substituted tin porphyrins and an ethynyl-linked tin porphyrin dimer

摘要

Time-dependent density functional theory calculations have been employed to characterize the inter-macrocycle interactions introduced when two tin(IV) porphyrins are axially covalently bonded via an ethynyl linker. The effect of changing the relative orientations of the two metalloporphyrin macrocycles is explored, with particular attention given to electronic states at energies up to the Soretcorrelated states in the dimer. Expansion of the Gouterman four orbital approach for the monomer to an eight orbital approach in the dimer produces a satisfactory analysis. The results are used to examine the feasibility of using such linked structures in photon harvesting schemes.