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(p-H),IrH2(PEt3)2]+[BPhha4s] b-e en 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 P2,/c and 2 = 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, p = 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) 8, 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 twoterminal 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.