Bisphenol Flukicides. V. The Crystal and Molecular Structures of 2,2'-(2,2-Dichlorovinylidene)bis(4-chloro-6-nitrophenol) and 4,4'-(2,2-Dichlorovinylidene)bis(2-chloro-6-nitrophenol)

Abstract

Crystals of 2,2'-(2,2-dichlorovinylidene)bis(4-chloro-6-nitrophenol) (1), C₁₄H₆C1₄N₂0₆, are monoclinic and belong to the space group C2/c with a 17.135(5), b 7.201(2), c 15.406(5) Å, β 118.40(2)º, Z 4. Orthorhombic crystals of the isomeric compound, 4,4'-(2,2-dichlorovinylidene)bis(2-chloro-6-nitrophenol) (2), belong to the space group P bcn with a 20.410(3), b 8.682(2), c 18.716(3) Å, Z 8. The structures were deduced from diffractometer data. For (1), refinement with 956 terms measured with Mo Kα radiation converged at R 0.055; structure (2) was refined with 1475 terms measured with Cu Kα radiation to R 0.079. Molecule (1) has exact C₂ symmetry, and the dihedral angle between the perpendiculars to the plane of the C-C-C bridge and the phenyl rings of 84.2(4)º defines a butterfly conformation. The conformation of (2) is twist with dihedral angles between the perpendiculars to the C-C-C bridge and phenyl rings of 61 .9(7) and 33.0(7)º.