Vinyliden‐übergangsmetallkomplexe, XVII. Synthese von trans ‐[IrCl(=C=CH 2 )(PR 3 ) 2 ] (PR 3 = PMe t Bu 2 , PPh 3 ), [IrHCl(CCPh)(PMe 2 t Bu) 3 ] und einigen Dihydridoiridium(III)‐Komplexen

Vinylidene Transition‐Metal Complexes, XVII. — Synthesis of trans ‐[IrCl(=C=CH 2 )(PR 3 ) 2 ] (PR 3 = PMe t Bu 2 , PPh 3 ), [IrHCl(CCPh)(PMe 2 t Bu) 3 ], and of some Dihydridoiridium(III) Complexes [IrCl(C 8 H 14 ) 2 ] 2 ( 1 ) reacts with PMe t Bu 2 in the presence of H 2 to give [IrH 2 Cl(PMe t Bu 2 ) 2 ] ( 2 ). Treatment of 2 with acetylene yields the vinylidene complex trans ‐[IrCl(=C=CH 2 )‐(PMe t Bu 2 ) 2 ] ( 3 ). The reaction of 1 with PMePh 2 or PMe 2 t Bu in the presence of H 2 leads to the formation of fac ‐[IrH 2 Cl(PR 3 ) 3 ] ( 4a , 5a ), which on warming to 60°C rearrange to give the more stable mer isomers 4b , 5b . Treatment of 1 with PMePh 2 or PMe 2 t Bu and phenylacetylene affords the hydrido(phenyl‐ethynyl)iridium(III) compounds mer ‐[IrHCl(CCPh)(PR 3 ) 3 ] ( 8, 9 ), which could not be converted by phosphine elimination to the corresponding (phenylvinylidene)iridium complexes. The synthesis of trans ‐[IrCl(=C=CH 2 )(PPh 3 ) 2 ] ( 11 ) has been achieved by CO abstraction from [IrHCl(CCH)(CO)(PPh 3 ) 2 ] ( 13 ) by using trimethylamine oxide.