The crystal and molecular structure of 4,4'-dichlorodiphenyl sulphone

4,4'-dichlorodiphenyl sulfone forms monoclinie crystals, space group I2/a, in a cell with a = 20.204 0-010, b = 5.009 0.010, c = 12.259 _ 0.010 A, fl = 90 34' 15', containing four molecules. The crystal structure has been solved by two-dimensional Patterson and by trial-and-error methods. The position and thermal vibration parameters were initially refined by use of double Fourier series. Final refinement was obtained by a complete anisotropic least-squares analysis of the 1158 observed and 548 unobserved structure factors. The three position and six thermal parameters of all atoms except hydrogen have been determined. The bond distances of interest include S-C = 1.765 0.006, S-O = 1.432 0.005, C-C = 1.380 0.003, C1-C = 1.736 0-007 A; among the bond angles are C-S-O = 107 39' + 17', C-S-C = 104 48' 24', O-S-O = 120 24' + 25'. The dihedral angle between the planes of the aromatic rings is 79 27'_+ 18' and between the plane of each ring and the common C-S-C plane it is 84 25'_ 18'.