Supramolecular architecture of two charge-transfer complexes based on 2,7-(X,X)-4,5-dinitro-9-dicyanomethylenefluorenes (X=NO2 or CN) and tetrathiafulvalene

Abstract

The crystal packings of two charge-transfer complexes based on tetrathiafulvalene and substituted fluorenes-2,4,5,7-tetranitro-9-dicyanomethylenefluorene (in complex 1) or 2,7-dicyano-4,5-dinitro-9-dicyanomethylenefluorene (in complex II)-are analyzed. Crystals of complex 11 involve a third component, namely, C6H5Cl solvate molecules. Crystals of both complexes are characterized by the formation of stacks composed of alternating donor and acceptor molecules and sheets in which the molecules are linked through different-type weak interactions. In structure 11, chlorobenzene molecules occupy cavities that are formed in stacks in the vicinity of the tetrathiafulvalene molecules due to the larger difference in size of the donor and acceptor molecules in complex 11 as compared to that in complex I. The chlorobenzene molecules provide a close packing. These molecules are involved in the system of weak interactions to form the Cl...N and C-H...N secondary bonds with the CN groups of the acceptor molecules in the sheets. (C) 2002 MAIK "Nauka/Interperiodica"