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The Photolysis of Chlorocarbonylbis(triphenylphosphine)iridium(I) in Chloroform
Author(s) -
Witter Brian M.,
Karabulut Merve,
Hoggard Patrick E.
Publication year - 2008
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2008.00382.x
Subject(s) - iridium , triphenylphosphine , chloroform , photodissociation , chemistry , photochemistry , organic chemistry , catalysis
Under 254 or 313 nm irradiation in chloroform, [IrCl(CO)(PPh 3 ) 2 ] is converted cleanly to [IrCl 2 (CO)H(PPh 3 ) 2 ] through the addition of HCl, produced photochemically. Under 254 nm irradiation, some of the reaction of [IrCl(CO)(PPh 3 ) 2 ] occurs by direct photolysis of chloroform, though a greater contribution arises from a reaction initiated through absorption of light by the metal complex. Under 313 nm irradiation, essentially all of the reaction is metal‐initiated. The linear dependence of the reaction rate on light intensity and on the fraction of light absorbed by the Ir(I) complex as well as the lack of a deuterium isotope effect rule out a radical process. Instead it is proposed that an association complex between excited state [IrCl(CO)(PPh 3 ) 2 ] and CHCl 3 leads to dissociation of a chlorine atom from CHCl 3 , yielding HCl after abstraction of a hydrogen from another CHCl 3 . HCl then adds to a ground state [IrCl(CO)(PPh 3 ) 2 ] complex.