Crystal Structure of Three Compounds Related to Triphenylene and Tetracyanoquinodimethane

The crystal structures of a charge-transfer complex of triphenylene with 1,3,5-tris(2,2-dicyanovinyl) benzene (1), a complex of 2,3,6,7,10,11-hexamethoxytriphenylene with 2,5-dichlorotetracyanoquinodimethane (2) and also 2,5-dichlorotetracyanoquinodimethane itself (3) have been determined. Compound 1 is triclinic, space group P (1) over bar, with a = 7.055(1), b = 11.026(2), c = 17.214(3) Angstrom. alpha = 96.59 (3), beta = 90.34(3), gamma = 91.61(3)degrees. Compound 2 is triclinic, space group P (1) over bar, with a = 12.228(2), b = 12.994(3), c = 13.702(3) Angstrom, alpha = 70.72(3), beta = 83.73(3), gamma = 66.06(3)degrees. Compound 3 is monoclinic, space group I2/a (C2/c), with a = 13.692(3), b = 7.7183(15), c = 16.391(3) Angstrom, beta = 99.47(3)degrees. The structures of 1 and 2 consist of mixed stacks of donors and accepters. The structures of 2 and 3 both include 1,2-dichlorobenzene solvent molecules. Weak hydrogen bonds are present in the structures of 1 and 2. Based on comparisons of bond lengths the electronic charge-transfer in 2 has been estimated to be about 0.3 e. The synthesis of 1,3,5-tris(2,2-dicyanovinyl) benzene is also reported.