Basische metalle: LI. Neuartige hydridorhodium(III)- und -iridium(III)-komplexe mit triisopropylphosphan-liganden. Die dihydrido-verbindungen C5H5MH2(PR′3) als metall-basen☆

The coordinatively unsaturated compound [RhCl(PR′ 3 ) 2 ] (I), which has been isolated as violet crystals, reacts with H 2 to form [RhH 2 Cl(PR′ 3 ) 2 ] (II). The reaction of II with NaC 5 H 5 gives only minor amounts of C 5 H 5 RhH 2 (PR′ 3 ) (IV). This dibydrido complex has been prepared in good yields either from C 5 H 5 Rh(OCOCF 3 ) 2 (PR′ 3 ) (III) and Na[AlH 2 (OC 2 H 4 OMe) 2 ] (Red-al) or from C 5 H 5 RhHCl(PR′ 3 ) (V) and LiAlH 4 . On protonation of IV with CF 3 CO 2 H/NH 4 PF 6 , the PF 6 salt of the dinuclear complex [(C 5 H 5 RhPR′ 3 ) 2 (μ-H 3 ] + (VI) is obtained. In contrast, treatment of the corresponding dihydridoiridium compound C 5 H 5 IrH 2 (PR′ 3 ) (IX) with HBF 4 ·Et 2 O gives the BF 4 salt of the mononuclear iridium(V) cation [C 5 H 5 IrH 3 (PR′ 3 )] + (X). Compound IX is obtained either from [IrH 2 Cl(PR′ 3 )py] (VIII) and NaC 5 H 5 or from C 5 H 5 Ir(OCOCF 3 ) 2 (PR′ 3 ) and Red-al. The reactions of [IrCl(PR′ 3 ) 2 ] with H 2 , HCl and HI give the five-coordinate complexes [IrH 2 Cl(PR′ 3 ) 2 ] (VII), [IrHCl 2 (PR′ 3 ) 2 ] (XI) and [IrHClI(PR′ 3 ) 2 ] (XII), which in the presence of pyridine form the octahedral compounds VIII, [IrHCl 2 (PR′ 3 ) 2 py] (XIII) and [IrHClI(PR′ 3 ) 2 py] (XIV), respectively. Structural proposals for the two isomers of XII and XIV are discussed.