Aggregation‐Induced Phosphorescent Emission from ReI Complexes: Synthesis and Property Studies

Four ReI complexes with aggregation‐induced phosphorescent emission (AIPE) were synthesized with the formula Re(CO)3(Bath‐n)Br (n = 1–4), where Bath‐1 = 4,7‐diphenyl‐2‐[4‐(trimethylsilyl)‐phenyl]‐1,10‐phenanthroline (1), Bath‐2 = 4,7‐diphenyl‐2‐[4‐(dimethylphenylsilyl)phenyl]‐1,10‐phenanthroline (2), Bath‐3 = 4,7‐diphenyl‐2‐[4‐(methyldiphenylsilyl)phenyl]‐1,10‐phenanthroline (3), and Bath‐4 = 4,7‐diphenyl‐2‐[4‐(triphenylsilyl)phenyl]‐1,10‐phenanthroline (4), and fully characterized. The single crystals of 1 and 3 were obtained in the monoclinic crystal system by diffusion of diethyl ether into their dichloromethane solutions. Complexes 1–4 in pure THF (c ≈ 10–5 mol L–1) mainly present π* → π emission at 370 nm and intraligand charge‐transfer (ILCT) emission at 440 nm, whereas the powder samples of 1–4 solely give lower energy 3MLCT (metal‐to‐ligand charge transfer) emission at approximately 560 nm. The lifetimes of the powder samples of 1–4 were measured at room temperature to be 0.335 µs, 0.149 µs, 0.289 µs, and 1.301 µs, respectively. Additionally, the emission spectra and the UV/Vis absorption spectra of 1–4 were analyzed in different THF/H2O mixtures to investigate their AIPE character. Furthermore, the ground states and the UV/Vis absorption spectra of 1–4 were also theoretically simulated at the B3LYP/(LANL2DZ+6‐31G) level.