Photophysical Properties of a Series of Rhenium Selenide Cluster Complexes Containing Nitrogen‐Donor Ligands

Abstract

Abstract The photophysical properties of rhenium selenide cluster complexes containing various nitrogen‐donor ligands (nitrile, azide, tetrazolate, and triazolate) are reported. These octahedral clusters are all based on the site‐differentiated [Re 6 Se 8 ] 2+ core and have the general formula [Re 6 Se 8 (PEt 3 ) 5 L] n + (L = nitrogen‐donor ligand). The excited‐state lifetimes, emission quantum yields, the rates of radiative and nonradiative decay, and the rate of quenching with O 2 are reported for thirteen different cluster complexes. The longest excited‐state lifetime was found for [Re 6 Se 8 (PEt 3 ) 5 ( p ‐aminobenzonitrile)][BF 4 ] 2 . The series of benzonitrile and phenyl‐substituted tetrazolate complexes allowed us to investigate the electronic impact of the para substituent; electrochemical and computational studies support metal‐to‐ligand charge transfer character in the excited‐state wave function for the p ‐nitrobenzonitrile complex. Notably, the substituents of the benzonitrile ligands have a greater effect on the photophysical properties than the substituents of the phenyltetrazolate ring.