STRUCTURE OF THE 1 1-CHARGE-TRANSFER COMPLEX BETWEEN TRITHIA[5]HETEROHELICENE AND 3,5-DINITROBENZOIC ACID - DEFORMATION OF HELICENE MOLECULES IN CRYSTALS/

The crystal and molecular structure of the title charge-transfer (CT) complex was determined by X-ray crystallographic analysis. Thieno[3,2- e:4,5-e'] di[1]-benzothiophene ([5]TH) and 3,5-dinitrobenzoic acid are alternately aligned with a separation of ca. 3.8 Angstrom to produce one-dimensional columns along the B-axis. Within a column, the chirali ty of [5]TH, having a labile helical structure, is confined to either type of enantiomer. A comparison of three CT complexes of [5]TH with d ifferent accepters showed the propensity for planarity of the [5]TH mo lecule in the complex to increase with reduction of the electron affin ity of the acceptors.