Side-bonded ketone complexes of platinum(0). Indan-1,2,3-trione complexes; molecular and crystal structure of [2,2′,-bis(indan-1,2,3-trionato)(2–)-O2O2′]bis(triphenylphosphine)platinum

Abstract

Reactions of equimolar quantities of [PtL₄](L = PPh₃ or AsPh₃) with either indan-1,2,3-trione (int) or 2,2-di-hydroxyindan-1,3-dione afford the side-bonded ketone complexes [Pt(int)L₂] which undergo ring-expansion reactions with int to give [Pt{(int)₂}L₂]. Crystals of the adduct [Pt{(int)₂}(PPh₃)₂] are monoclinic, space group Cc with a= 22.08, b= 14.47, c= 30.72 Å, β= 95.1°, and Z= 8. Least-squares refinement of the structural parameters reduced R to 0.078 for 2 382 reflections. The adduct has the two indan-1,2,3-trione moieties linked via the carbon atoms of the central carbonyl groups and bonded by the oxygen atoms at these groups to the platinum to give a five-membered 1,3-dioxa-2-platinolan ring. Ring-expansion reactions of [Pt(int)L₂] and ring-substitution reactions of [Pt{(int)₂}L₂], with hexafluoropropan-2-one and hexafluorobut-2-yne are also described. Reactions with hexafluoropropan-2-one give both five- and seven-membered ring systems. The side-bonded complexes [Pt(int)L₂] react with dioxygen to give cyclic dicarboxylato-complexes.