January 2013 issue
Cover illustration: Calixthiophenes are sulfur-based analogues of calixarenes and are interesting materials in supramolecular chemistry. In the compound [Ge4(CH3)8(C4H2S)4], four C atoms in the cyclic backbone are replaced by Ge atoms to form a hetero-calixthiophene. The dihedral angle between adjacent thiophene rings in the centrosymmetric molecule is 72.84 (14)° so that S atoms of opposite thiophene rings are either adjusted towards or nearly perpendicular to the centre of the ring. See: Carel, Mallet-Ladeira, Rima, Madec & Castel [Acta Cryst. (2013). E69, m37].