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Photochemical Reactions of [(η 5 ‐C 5 R 5 )Re(CO) 3 ] (R = Me or H) with Aryl Halides in Benzene: Stoichiometric Formation of Biphenyl
Author(s) -
Zhu Bolin,
Huang Xinwei,
Hao Xiaoting
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402793
Subject(s) - chemistry , rhenium , biphenyl , aryl , benzene , chlorobenzene , halide , hydride , photochemistry , bromobenzene , medicinal chemistry , photodissociation , stoichiometry , catalysis , inorganic chemistry , alkyl , organic chemistry , metal
Photolysis of [Cp*Re(CO) 3 ] (Cp* = η 5 ‐C 5 Me 5 ) with bromobenzene or chlorobenzene in benzene results in biphenyl and the corresponding rhenium hydride halide complex trans ‐[Cp*Re(CO) 2 H(X)], which further converts into the dihalide complexes cis / trans ‐[Cp*Re(CO) 2 X 2 ] (X = Br, Cl). Additional experiments, including isotopic labeling experiments, indicate that one phenyl ring in biphenyl comes from the aryl halide and the other one comes from solvent benzene. Photolysis of [CpRe(CO) 3 ] (Cp = η 5 ‐C 5 H 5 ) with aryl halide in benzene similarly generates biphenyl, the corresponding rhenium hydride halide complex. Furthermore, the reaction also affords small amounts of rhenium dihydride complex [CpRe(CO) 2 H 2 ]. Plausible mechanisms for the formation of the different types of products are proposed that involve intermolecular C–X and C–H activation. Molecular structures of trans ‐[Cp*Re(CO) 2 (Br)(Cl)] ( trans ‐ 6 ) and trans ‐[CpRe(CO) 2 (Br)(Cl)] ( trans ‐ 12 ) determined by X‐ray diffraction are also presented.