Synthesis, characterisation and photochemistry of platinum diselenolenes

Abstract

The reaction between [Pt(PPh₃)₄] and cycloocteno-1,2,3-selenadiazole or bis-cycloocteno-1,4-diselenin in toluene under reflux yielded the poorly soluble mononuclear platinum diselenolene [Pt(Se₂C₈H₁₂)(PPh₃)₂], 1c. Treatment of [Pt(C₂H₄)(PR₃)₂] with a bis-cycloalkeno-1,4-diselenin in a mixture of 1,4-dioxane, THF and toluene under reflux led in good yield to the platinum diselenolenes [Pt(Se₂C_n+4H_2n+4)(PR₃)₂] (R = Et (2), Bu (3); n = 3 (b), 4 (c)). The analogous complexes [Pt(Se₂C₈H₁₂)(L)] (L = dppm: 4c; L = dppe: 5c; L = dppp: 6c) were prepared from 1cvia ligand exchange with chelating phosphines. All new compounds have been characterised by multinuclear NMR, IR and UV-visible spectroscopy and mass spectrometry, and their luminescence properties have been examined. The molecular structures of [Pt(Se₂C₇H₁₀)(PEt₃)₂] (2b), [Pt(Se₂C₈H₁₂)(PEt₃)₂] (2c) and [Pt(Se₂C₈H₁₂)(dppm)] (4c) have been determined by X-ray crystallography.