Synthesis and Photophysical Evaluation of 3,3’‐Nitrogen Bis‐Substituted $fac$‐[Re(CO)$_3$(Diimine)Br] Complexes

Abstract

The preparations, photophysical and electrochemical properties of a series of fac‐[Re(CO)$_{3}$(diimine)Br] complexes are presented. The bipyridine (bpy) based diimine ligands feature symmetrical and asymmetrical 3,3’‐diamino‐2,2’‐bipyridine substitution patterns. Photophysical and electrochemical properties of these complexes are tunable, depending on their organic diimine framework. Introduction of a distal urea bridge via the 3,3’‐substitution pattern led to prolonged phosphorescence lifetimes without a significant change in absorbance and phosphorescence emission wavelengths. Reversible electrochemical bipyridine reduction remained largely unchanged by this derivatization.