LI2PTH2, SYNTHESIS AND STRUCTURE

The synthesis of Li2PtH2 succeeded in decomposing Li5Pt2H9 at 220 degr ees C in an argon atmosphere. X-ray investigations on a powdered sampl e and elastic neutron diffraction experiments on the deuterated compou nd led to the complete structure. Li2PtH2 crystallizes in the space gr oup Immm with Z = 2. The structure is characterized by [PtH2](2-)-dumb -bells which are hitherto unknown in platinum compounds. The arrangeme nt of the [PtH2](2-)-anions and of the lithium cations shows a close r elationship to the hydride Li2PdH2 which crystallizes tetragonal I-cen tred.