The crystal structure of 9-chloro-4,5-dihydro-2-ethyl-1-(2,4,6-trichlorophenyl)-1H-1,2,4-triazolo[3,2-d][1,5]-benzoxazepinium hexachloroantimonate

The title compound 4, i.e. 9-chloro-4,5-dihydro-2-ethyl-1-(2,4,6-trichlorop henyl)-1H-1,2,4-triazolo[3,2-d]- [1,5]benzoxazepinium hexachloroantimonate, is a novel 6-7-5 tricyclic heterocycle. C18H14Cl4N3O . SbCl6, M = 764.61, P2(1)/c(#14), a = 13.457(4), b = 11.583(2), c = 18.992(3) Angstrom; alpha = 90, beta = 110.11(1)degrees, Z = 4, V = 2780(1) Angstrom(3), D-c = 1.827 g /cc, mu (MoK alpha) = 19.69 cm(-1), F(000) = 1488.00, T = 293 K, R-int = 0. 055 for 3094 independent reflections with I>3.00 sigma(I). The five-membere d heterocyclic ring is nearly planar, with the trichlorophenyl ring at N(2) almost perpendicular to it. However, the seven-membered ring is not planar , but adopts a twist-boat conformation.