Synthesis and Reactivity of Platinum(II) <i>cis</i>-Dialkyl, <i>cis</i>-Alkyl Chloro, and <i>cis-</i>Alkyl Hydrido Bis‑<i>N</i>‑heterocyclic Carbene Chelate Complexes

Platinum­(II) <i>cis-</i>dimethyl and <i>cis-</i>dineopentyl complexes bearing the alkyl-substituted bis-NHC ligands L^{<i>t</i>‑Bu}, L^Me, and L^{<i>i</i>‑Pr} (L^{<i>t</i>‑Bu} = 1,1′-di-<i>tert</i>-butyl-3,3′-methylenedi­imid­azolin-2,2′-diylidene, L^Me = 1,1′-dimethyl-3,3′-methylenedi­imid­azolin-2,2′-diylidene, L^{<i>i</i>‑Pr} = 1,1′-diisopropyl-3,3′-methylenedi­imid­azolin-2,2′-diylidene) as well as novel <i>cis-</i>alkyl chloro and <i>cis-</i>alkyl hydrido compounds were synthesized. The reactivity of the dimethyl complexes toward dichloromethane and methanol was investigated. Reductive elimination of alkanes from <i>cis-</i>alkyl hydrido complexes requires much higher temperatures than in related bisphosphine systems, which limits their applicability for the generation of reactive, bent platinum(0) d¹⁰-ML₂ fragments for bond-activation chemistry. The platinum­(II) complexes were characterized by NMR and IR spectroscopy, mass spectrometry, elemental analysis, and X-ray diffraction in most cases