Synthesis and Characterization of the First Acyl(hydrido)platinum(IV) Complexes

The platina-β-diketone [Pt<sub>2</sub>{(COMe)<sub>2</sub>H}<sub>2</sub>(μ-Cl)<sub>2</sub>] (<b>1</b>) reacts with 2,2‘-bipyridine (bpy), 4,4‘-dimethyl-2,2‘-bipyridine (me<sub>2</sub>bpy), or 4,4‘-di(<i>tert</i>-butyl)-2,2‘-bipyridine (<i>t</i>-bu<sub>2</sub>bpy) to give novel acyl(hydrido)platinum(IV) complexes [PtCl(H)(COMe)<sub>2</sub>(NN)] (NN = bpy (<b>2a</b>), me<sub>2</sub>bpy (<b>2b</b>), <i>t</i>-bu<sub>2</sub>bpy (<b>2c</b>)). The complexes <b>2</b> show an astonishing thermal stability in the solid state up to 180 °C. They decompose with cleavage of acetaldehyde to form the acylplatinum(II) complexes [PtCl(COMe)(NN)] (<b>3</b>). The identities of <b>2</b> and <b>3</b> were determined by microanalysis and NMR (<sup>1</sup>H, <sup>13</sup>C) and IR spectroscopies. The crystal structure of [PtCl(H)(COMe)<sub>2</sub>(<i>t</i>-bu<sub>2</sub>bpy)] (<b>2c</b>) has been determined. The Pt−H bond distance was found to be 1.72(5) Å.