Neuartige basische Liganden fu¨r die homogenkatalytische Methanolcarbonylierung: XIV. Synthese von Ether-Phosphan-Komplexen des Iridiums und ihr Verhalten gegenu¨ber Wasserstoff

Abstract The cationic complex [(COD)Ir( P O ⌢ )] [ BF 4 ] ( 3 ) is formed upon addition of AgBF 4 on the iridium complex (COD)IrCl(P ∼ O) ( 2 ) (P ∼ O = cyclo-(C 6 H 11 ) 2 PCH 2 CH 2 OCH 3 ) with Cl − abstraction and subsequent occupation by the ether oxygen atom of the empty coordination site. 2 is obtained from the reaction of [μ-ClIr(COD)] 2 ( 1 ) with the P, O ligand cyclo-(C 6 H 11 ) 2 PCH 2 CH 2 OCH 3 . In the presence of H 2 and cyclo-(C 6 H 11 ) 2 PCH 2 CH 2 OCH 3 the reactive Ir-O bond in 3 is cleaved with formation of the cis -dihydridoiridium complex, H 2 Ir(COD)(P ∼ O) 2 ( 4 ). Reaction of [μ-ClIr(COE) 2 ] 2 ( 5 ) with cyclo-(C 6 H 11 ) 2 PCH 2 CH 2 OCH 3 leads to the trans -dihydridoiridium complex H 2 IrCI ( P O ⌢ ) ( P~O ) ( 6 ) during which COE is partially dehydrogenated to COD (COD = cyclooctadiene; COE = cyclooctene).