Synthesis and crystal structure of the molecular complex of fullerence C60 with 2-(4-thiono-1,3-dithiolan-5-ylidene)-4,5-dimethyl-1,3-diselenol (C60·2DTDS)

Abstract

A new molecular complex of fullerene C60 with 2-(4-thiono-1,3-dithiolan-5-ylidene)-4,5-dimethyl-1,3-diselenol (C60·2DTDS) was synthesized for the first time. The crystal and molecular structures of C60·2DTDS were established by X-ray diffraction analysis. The crystal structure of C60·2DTDS is layered: the layers of fullerene C60 molecules alternate with those of DTDS molecules. The molecules of C60 and DTDS are associated by shortened C...Se, C...S, and C...C contacts forming a three-dimensional network of secondary interactions in the crystal. The C60·2DTDS crystals have a specific feature: the absence of shortened C...C contacts between the nearest C60 molecules despite the short distances between their centers, 9.948(2) and 10.054(2) A. The electrochemical properties of DTDS were studied by cyclic voltammetry in CH2Cl2/0.05M Bu4NPF6 at room temperature. DTDS undergoes reversible one-electron reduction to a radical anion [Eo=−1.81 V (Fc0/+)] and reversible one-electron oxidation to a radical cation [Eo=+0.37 V (Fc0/+)]. The degree of charge transfer in C60·2DTDS, ΔN=0.18, calculated from the electrochemical parameters of DTDS and C60 indicates that this compound is a molecular complex with a partial charge transfer.