Structural and Photophysical Trends in Rhenium(I) Carbonyl Complexes with 2,2':6',2″-Terpyridines.

This is the first comprehensive review of rhenium(I) carbonyl complexes with 2,2':6',2″-terpyridine-based ligands (R-terpy)-encompassing their synthesis, molecular features, photophysical behavior, and potential applications. Particular attention has been devoted to demonstrating how the coordination mode of 2,2':6',2″-terpyridine (terpy-κ 2 N and terpy-κ 3 N), structural modifications of terpy framework (R), and the nature of ancillary ligands (X-mono-negative anion, L-neutral ligand) may tune the photophysical behavior of Re(I) complexes [Re(X/L)(CO) 3 (R-terpy-κ 2 N)] 0/+ and [Re(X/L)(CO) 2 (R-terpy-κ 3 N)] 0/+ . Our discussion also includes homo- and heteronuclear multicomponent systems with {Re(CO) 3 (R-terpy-κ 2 N)} and {Re(CO) 2 (R-terpy-κ 3 N)} motifs. The presented structure-property relationships are of high importance for controlling the photoinduced processes in these systems and making further progress in the development of more efficient Re-based luminophores, photosensitizers, and photocatalysts for modern technologies.