Photochemical and photophysical processes in fac-Re(CO) 3−(4-phenylpyridine) 3(CF 3SO 3). Steady state and flash photolysis study

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 1996-12, Vol.101 (2), p.119-125
• Main Authors: Ruiz, G., Wolcan, E., Féliz, M.R.
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Flash photolysis; General and physical chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Re complexes; Steady state photolysis
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/S1010-6030(96)04423-1

The photophysics and photochemistry of fac-Re(CO) 3(4-phenylpyridine) 3 + were investigated by monochromatic steady state and flash photolysis. Two parallel photoprocesses, photogeneration of the emissive metal-to-ligand charge transfer (MLCT) state and photoredox dissociation in [Re(CO) 3(4-phenylpyridine) 2 2+, (4-phenylpyridine −)], were observed. In the former process, the emission originating from the lower MLCT excited state is electron transfer quenched by triethanolamine (TEOA) producing an Re(CO) 3(4-phenylpyridine) 3 radical and energy transfer quenched by Cu(TIM) 2+ (TIM ≡ 2,3,9,10-tetramethyl-[14]-1,4,8,11-tetraene-N 4). The primary species Re(CO) 3(4-phenylpyridine) 2 2+ generated in the latter photoprocess undergoes several thermal changes which finally lead to dimeric products. A third photoprocess, namely the photogeneration of the [Re(CO) 3(4-phenylpyridine) 2 2+ (4-phenylpyridine −)] species, is involved in the reduction of the copper macrocycle to Cu(TIM) +.