Crystal Structure of TTF·BTDA–TCNQ Complex. A New Type of CT Complex with an Inclusion Behavior and a Multi-Dimensional Structure

The crystal structure of TTF·BTDA–TCNQ complex was determined by an X-ray diffraction method. The crystals are monoclinic, space group P21⁄n with a=9.660(1), b=7.231(1), c=14.628(2) Å, β=91.31(1)°, and Z=2. The structure was solved by the direct method and refined by the block-diagonal least-squares method to give an R value of 0.040 for non-zero 2620 reflections. The complex is nonionic and the molecules form equally spaced mixed stacks along the b axis. These stacks are connected by strong transverse interactions resulting in a three-dimensional structure. BTDA–TCNQ molecules make cavities by S–N≡C interactions in which TTF molecules are included. This complex is not a simple CT complex with mixed stacks but rather the one with some inclusion behavior.