On the Characteristic and Dynamics of Excited States Populated After Excitation at Soret-like Band of Dibenzo[g,p]chrysene-fused Bis-Dicarbacorrole Cu(III) and Pd(II) Metal Complexes

Abstract

Dibenzo [g,p]chrysene-fused Bis-Dicarbacorrole (Bis-H 3 ) metal complexes show unique electron configurations and properties depends on the number and the type of coordinated metal centers as there are two coordinative adj-CCNN subunits. When Cu(III) ions coordinated in, π electrons in Bis-H 3 ligand maintains and when Pd(II) ions coordinated in, each Pd(II) would induce one π electron from Bis-H 3 ligand donated to the Pd center so the electron configuration and aromaticity of Bis-H 3 ligand could be modified by introducing Pd(II) centers coordinated in. In this research, by applying transient absorption spectroscopy with probe range in both visible range and near infrared range, together with density functional theory and time-dependent density functional theory calculations. It was found that for Bis-H 3 complexes only with Cu(III) centers, ligand-to-metal charge transfer state could be populated after excitation at its Soret-like band but for complexes include Pd(II) metal centre, metal-to-ligand charge transfer state is populated instead and its lifetime is much longer than Cu(III) only Bis-H 3 complex. The Pd(II) included Bis-H 3 complex's charge recombination rate is also found high corresponding with electron hole distance of the excited state populated. For Bis-H 3 metal complexes, photoinduced electron transfer direction and corresponding charge recombination rate could be modified by changing the metal centers coordinated in.