X-ray and neutron diffraction study of the new cationic bis(hydrido)-bridged platinum-iridium complex [(PEt3)2Pt(.mu.-H)2IrH2(PEt3)2 ]+[BPh4]

The structure of [(PEt3)2pt(μ-H)2IrH2(PEt3)2]+[BPh4]-has been studied by X-ray and neutron diffraction techniques, at room temperature and 22 (1) K, respectively. At both temperatures, crystals of the title compound are monoclinic, with space group P21/c and Z = 4. Unit cell parameters at 22 K are as follows: a = 18.989 (10) A, b = 15.314 (3) A, c = 19.792 (6) A, β = 118.73 (3)°, and V = 5047 (4) A3. The coordination around the Ir atom is distorted octahedral, while that around Pt is distorted square planar. The neutron analysis shows that the Pt-Ir distance is 2.677 (1) A and that the distances between the metals and bridging hydrido ligands differ by 0.15 A (Ir-H = 1.879 (3) and 1.882 (3) A; Pt-H = 1.726 (3) and 1.736 (3) A). The two terminal Ir-H bonds are equivalent (1.586 (3) and 1.591 (3) A) and comparable in length to those found in other neutron diffraction studies.