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

Four Re I 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 3 MLCT (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/H 2 O 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.