The Crystal Structure of the Charge-transfer Complex of Dibenzotetrathiafulvalene-Tetracyanoquinodimethane, DBTTF–TCNQ

Abstract

The crystal of the charge-transfer complex of dibenzotetrathiafulvalene-7,7,8,8-tetracyanoquinodimethane, DBTTF–TCNQ, belongs to the triclinic system; a=10.309(8), b=8.281(2), c=7.727(3) Å, α=110.03(4), β=109.80(4), γ=72.05(3)°, space group P\bar1 with Z=1. The structure has been determined by the X-ray method. DBTTF and TGNQstack alternately along [011] to form mixed columns; this phenomenon is responsible for the low electrical conductivity of DBTTF–TCNQ. The intermolecular distance between DBTTF and TCNQ is 3.303 Å. The charge-transfer complexes of DBTTF with TNB, TCNE, DDQ,and fluoro-TCNQ, were examined by means of X-ray photographs. It is shown that the DDQ, complex, exhibiting a high conductivity, has segregated uniform columns of donors and acceptors, such as were not found in the other complexes.