Conformational chirality of oligothiophenes in the solid state. X-ray structure of 3,4',4''-trimethyl-2,2':5',2''-terthiophene

Chiral crystals of organic compounds have many potential applications, particularly in laser technology. The first case among oligothiophenes of chirality in the solid state is reported, the crystal structure being given along with selected NMR data and force field MM2 calculations that provide information about the conformational properties of the compound in solution. Two structural features new for ?-conjugated oligothiophenes are exhibited: a chiral space group and a crystal packing that involves short van der Waals contacts.