Synthesis and studies of a novel [(Tetrathiafulvalene)-(2-Amino-6-nitrobenzothiazole)2] co-crystal

Publication date: 1 October 2013
Source:Journal of Crystal Growth, Volume 380
Author(s): Arun Boyineni , Subbalakshmi Jayanty , Raghavaiah Pallepogu
A novel 2-Amino-6-nitrobenzothiazole (2A6NBT) complex of tetrathiafulvalene (TTF) was synthesized and crystal structure of (TTF)-(2A6NBT)2 is reported. The asymmetric unit is found to have half molecule of TTF and one molecule of 2-Amino-6-nitrobenzothiazole. Several short interactions of type π–π, nonconventional Van der Waals and hydrogen bonding were observed in this complex. Localization of the inversion center lead to the presence of 2A6NBT moieties in the trans position. Van der Waals type short interactions existed predominantly between one TTF and six 2A6NBT molecules. The C–C bond length of 1.314Å in (TTF)-(2A6NBT)2 is the shortest C–C bond distance reported among the TTF molecules studied so far. TTF's and 2A6NBT molecules are nearly orthogonal to each other. TTF form segregated stacks along the c axis and exhibit a novel “stair case” structure. The extensive short interactions lead to supramolecular architectures. Two probe room temperature conductivity value of powder was (∼1.4×10⁻⁷ S/cm) found to be within the semiconducting range measurements. Density functional calculations using the hybrid functional B3LYP with 6–31G (d) basis set indicated thermodynamically favored product. Scanning electron microscopy images revealed rod like microstructures.