The crystal and molelcular structure of benzil bisthiosemicarbazonatocopper(II) and the antitumour mechanism of related compounds
The crystal structure of benzil bisthiosemicarbazonatocopper(II) has been solved and refined to an R-value of 0.082. The dark red triclinic crystal has cell dimensions a = 960.8(4), b = 1090.7(6), c = 895.8(4) pm, α = 106.23°(4), β = 92.36°(7), γ = 99.50°(7), and belongs to space group [Formula: see text] with two molecules per cell. The measured and calculated densities are 1.571 and 1.568 g cm−3, respectively, using C16H14CuN6S2 (mol. wt. 417.99). The copper coordination is significantly non-planar. The five non-hydrogen atoms of each original thiosemicarbazide molecule lie close to planes set at a dihedral angle of 8.9°. The fold is away from the origin and the neighbouring molecule. Bond lengths to copper are: Cu—S(1) = 223.7(3), Cu—S(2) = 223.4(3), Cu—N(13) = 197.1(6), Cu—N(23) = 197.0(7) pm. The bond angles at the Cu atom are S(1)—Cu—S(2) = 108.62°(9), N(13)—Cu—N(23) = 81.1°(3), N(13)—Cu—S(1) = 85.1°(2), and N(23)—Cu—S(2) = 85.0°(2). The first and second phenyl rings are at 100.3° and 93.0° to the mean Cu coordination plane, which is at a perpendicular distance of 330 pm from a similar plane in the inverse molecule. Intermolecular double hydrogen bonding occurs at each side of the complex between the uncoordinated nitrogen atoms, thus linking the molecules into parallel ribbons.