From platina-β-diketones to diacetylplatinum(II) complexes – Synthesis, characterization and structural features

The reaction of the electronically unsaturated platina-β-diketone [Pt2{(COMe)2H}2(μ-Cl)2] (1a) with N⌢N donors led to the formation of diacetyl(hydrido)platinum(IV) complexes [Pt(COMe)2Cl(H)(N⌢N)] (2). By the reaction of these complexes with NaOH in a two-phase system (H2O/CH2Cl2) diacetylplatinum(II) complexes [Pt(COMe)2(N⌢N)] (N⌢N = bpy, 4a; 4,4′-Me2-bpy, 4b; 4,4′-t-Bu2-bpy, 4c; 4,4′-Ph2-bpy, 4d; 4,4′-t-Bu2-6-n-Bu-bpy, 4e; bpym, 4f; bpyr, 4g; phen, 4h; 4-Me-phen, 4i; 5-Me-phen, 4j) were obtained. All complexes were characterized by microanalysis, IR and 1H and 13C NMR spectroscopy. Additionally, complexes 4a, 4c, 4d and 4e were characterized by single-crystal X-ray diffraction analysis. The observed variety of packing patterns resulting from π–π stacking and hydrogen bonding is discussed.

Diacetylplatinum(II) complexes (II) with chelating N⌢N ligands like 2,2′-bipyridine, 1,10-phenanthroline, 2,2′-bipyrimidine and 2,2′-bipyrazine were synthesized in a straightforward two step reaction starting from the platina-β-diketone [Pt2{(COMe)2H}2(μ-Cl)2] (I). The airstable complexes II were fully characterized by NMR and microanalysis. In the solid-state structures π–π stacking and hydrogen bonding were found to be important packing motifs.Figure optionsDownload as PowerPoint slide