Synthesis and Supramolecular Structure of a Novel π-Extended TTF Derivative

A novel pi-extended TTF derivative (C24H20N6S8, M-r = 649.02) has been synthesized and characterized by IR, H-1 NMR and MS. The crystal structure was prepared by crystallization from CH2Cl2-MeOH. The crystal belongs to the monoclinic system, space group P2(1)/c with a = 5.465(5), b = 26.835(5), c = 10.180(5) angstrom, beta = 101.929(5)degrees, V = 1460.7(15) angstrom(3), Z = 2, D-c = 1.476 g/cm(3), F(000) = 668, mu = 0.638 mm(-1), the final R = 0.0390 and wR = 0.0586 for 1694 observed reflections with I > 2 sigma(I). The structure reveals planarity of the two dithiole rings, different from the boat-shaped structure usually found in neutral derivatives of TTF. The central ring of the benzene also adopts a planar conformation, while it is twisted from planarity of the two dithiole rings and forms a dihedral angle of 61.8 degrees. The molecule exhibits a three-dimensional supramolecular architecture constructed through hydrogen bonds. In the molecular structure a noticeable feature can be found that there exist S center dot center dot center dot S interactions which further reinforce the 3D supramolecular framework.