TpRe photolysis

Scheme 2. Photolysis of TpRe( = 0)(I)(Cl) (5) in C6H6 to produce TpRe( = 0)(Cl)(C6H5) (7).

Photolysis of 7 in the presence of DMSO (DMSO = dimethylsulfoxide), py or NCMe yields the phenoxide complex TpRe(OPh)(Cl)(L) (L = O, py or NCMe) (Scheme These transformations likely occur via an intramolecular [l,2]-shift... 

Photolytic alkyl migration to a Re-oxo has also been observed. TpRe(OEt)(Cl)(py) was prepared by the photolysis of TpRe( = 0)(Cl)(Et) in the presence of pyridine. In contrast to the analogous aryl migration, the formation of the Re(III) ethoxide system is thought to occur through the formation of ethyl radical. For example, photolysis of TpRe( = 0)(Cl)(Et) in the presence of PhSH produces TpRe( = 0)(Cl)(SPh) and ethane, which is consistent with initial bond homolysis of the Re-C bond of Re-CH2CH3. 

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