Synthesis and crystal structure of the molecular complex of fullerene C-60with 2-(4-thiono-1,3-dithiolan-5-ylidene)-4,5-dimethyl-1,3-diselenol (C-60center dot 2DTDS)

A new molecular complex of fullerene C-60 with 2-(4-thiono-1,3-dithiolan-5- ylidene)-4,5-dimethyl-1,3-diselenol (C-60.2DTDS) was synthesized for the fi rst time. The crystal and molecular structures of C-60.2DTDS were establish ed by X-ray diffraction analysis. The crystal structure of C-60.2DTDS is la yered: the layers of fullerene C-60 molecules alternate with those of DTDS molecules. The molecules of C-60 and DTDS are associated by shortened C...S e, C...S, and C...C contacts forming a three-dimensional network of seconda ry interactions in the crystal. The C-60.2DTDS crystals have a specific fea ture: the absence of shortened C...C contacts between the nearest C-60 mole cules despite the short distances between their centers, 9.948(2) and 10.05 4(2) Angstrom. The electrochemical properties of DTDS were studied by cycli c voltammetry in CH2Cl2/0.05 M Bu4NPF6 at room temperature. DTDS undergoes reversible one-electron reduction to a radical anion [E degrees = -1.81 V ( Fc(0/+))] and reversible one-electron oxidation to a radical cation [E degr ees = +0.37 V (Fc(0/+))]. The degree of charge transfer in C-60.2DTDS, Delt a N = 0.18, calculated from the electrochemical parameters of DTDS and C-60 indicates that this compound is a molecular complex with a partial charge transfer.