Hydrido-derivatives of [Ir4(CO)10(diphosphine)]: X-ray analyses of [Ir4H(CO)9(μ-Ph2PH(CH3)PPh2)]− and [Ir4 H(CO)9(μ-Ph2P(CH2)nPPh2)]− (n = 2, 3)

Abstract Some novel hydrido-anions of general formula [Ir 4 H(CO) 9 (μ-L–L)] − (L–L = Ph 2 PCH(CH 3 )PPh 2 , Ph 2 P(CH 2 ) 2 PPh 2 , Ph 2 P(CH 2 ) 3 PPh 2 and Ph 2 AsCH 2 AsPh 2 ) have been obtained by the reaction of [Ir 4 (CO) 10 (μ-L–L)] with the base 1,8-diazabicyclo[5.4.0]undec-7-ene in wet dichloromethane. According to IR and 1 H, 31 P and 13 C NMR data at low temperature, these anionic derivatives display a single conformation in solution: three edge-bridging COs around the triangular basal face and both the hydride and the bidentate ligands located in axial positions relative to this face. The structures of four compounds were established by X-ray diffraction studies, which confirmed the configuration proposed on the basis of spectroscopic data.