Photolytic CH activation and dehydrogenation of alkanes at cyclopentadienyl iridium complexes in a perfluorinated solvent

The fluorinated complex [(Cp f )Ir(CO) 2 ] ( 2 ) [Cp f = C 5 H 4 (CH 2 ) 2 (CF 2 ) 5 CF 3 ] serves as a precursor for the photolytic activation of CH bonds in alkanes to give [(Cp f )Ir(CH 3 )(H)(CO)] ( 3 ), [(Cp f )Ir(C 5 H 9 )(H)(CO)] ( 4 ), [(Cp f )Ir(C 6 H 11 )(H)(CO)] ( 5 ) or [(Cp f )Ir(C 8 H 15 )(H)(CO)] ( 6 ). In C 7 F 14 as a solvent the latter react to yield the corresponding olefins as well as [(Cp f )Ir(H) 2 (CO)] ( 7 ). Photocatalytic experiments revealed that [(Cp f )Ir(CO) 2 ] ( 2 ) and the non-fluorinated compound [(Cp)Ir(CO) 2 ] ( 1 ) dehydrogenate cyclohexane in C 7 F 14 . In C 6 H 12 as a solvent a decomposition of the catalysts was observed. The complexes [(Cp f )Ir(CO) 2 ] [Cp f = C 5 H 4 (CH 2 ) 2 (CF 2 ) 5 CF 3 ] and [(Cp)Ir(CO) 2 ] serve as precursors for a photochemical dehydrogenation of cycloalkanes. An oxidative addition of methane at iridium under mild conditions was also accomplished.