Structural and Electronic Properties of TXF-TCNQ (X ˭ S, Se, Te)

Abstract

Abstract We report the crystal structure and physical properties of TTeF-TCNQ, compare the electrical conductivities of TXF-TCNQ (X ˭ S, Se, Te) by performing tight-binding band calculations on TXF-TCNQ, and examine the differences in the packing patterns of TXF-TCNQ (X ˭ S, Se, Te) by carrying out ab initio SCF-MO/MP2 calculations on appropriate model systems. The electrical conductivity of TXF-TCNQ increases as X varies from S to Se to Te. This increase is primarily caused by the conductivity enhancement in the donor stacks. In TXF-TCNQ (X ˭ S, Se) the C-H bonds of both the donor and the acceptor molecules make intermolecular contacts shorter than the van der Waals radii sums, but in TTeF-TCNQ only the C-H bonds of the donor molecules do. This difference in the packing patterns was rationalized on the basis of the C-H…X and N(sp)…X (X ˭ S, Se, Te) contact interaction energies estimated by ab initio SCF-MO/MP2 calculations on H3C-H…XH2 and H-C≡N…XH2.