Flash photolysis study of the metal-metal bond homolysis in dimanganese decacarbonyl and dirhenium decacarbonyl

Abstract

Hexane solutions of Mn2(CO)10 and Re2(CO)10 have been subjected to flash photolysis. Under 1 atm of CO pressure, the absorbance due to the dinuclear species returns to the original value in accordance with a simple bimolecular rate law. This behavior suggests that the only process of importance in the solutions is bimolecular recombination of M(CO)s• radicals.The bimolecular rate constants obtained at 22 °C are kt = 9.5 X 108 M'1 s'1 for Mn2(CO)10 and 3.7 X 109 M'1 s'1 for Re2(CO)10. When the solutions are thoroughly degassed prior to flash photolysis, a more complex behavior is noted. Intermediates that are more strongly absorbing in the 350-500-nm region than the M2(CO)10 species are formed and then disappear over a period

Organometallic photochemistry at the end of its first century

“…6 [100]. Improvements in detectors and the introduction of pulsed lasers as light sources quickly drove these times to the ls [101] and ps range, Fig. 7 [102].…”

Multi-mode Polymerizations Involving Photoinduced Radical Polymerization

“…One of the most intensively used method is undoubtedly the use of manganese decacarbonyl (Mn 2 (CO) 10 ) together with alkyl halides. The pair yields reactive alkyl radicals upon visible light irradiation [18][19][20][21][22][23][24].…”

Cross-Selective Aza-Pinacol Coupling via Atom Transfer Catalysis

“…However, when proposed intermediate [Mn]−I, Zn, and amine were combined to initiate generation of the active [Mn•] species, reactivity was observed in the dark (51%). These data suggest photolysis is required only for initiation and when [Mn•] dimerization (k = 9.5 × 10 8 M −1 s −1 ) 52 occasionally outcompetes ketyl radical generation by iodine abstraction.…”