Structures of N-acetylbenzamide, N-propionylbenzamide and N-butyrylbenzamide and analysis of imide hydrogen-bond patterns.

N-Acetylbenzamide, C9H9NO2 (I) Mr = 163.18, orthorhombic, Pbca, a = 8.990 (2), b = 9.208 (3), c = 19.619 (3) A, V = 1624 (1) A3, Z = 8, Dx = 1.335 (1) g cm-3, lambda(Mo K alpha) = 0.710569 A, mu = 0.89 cm-1, F(000) = 688, T = 295 K, R = 0.031 for 865 observed reflections. N-Propionylbenzamide, C10H11NO2 (II), Mr = 177.20, monoclinic, P2(1)/c, a = 10.485 (2), b = 23.236 (4), c = 8.132 (2) A, beta = 108.43 (2) degrees, V = 1880 (1) A3, Z = 8, Dx = 1.252 (1) g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 0.82 cm-1, F(000) = 752, T = 297 K, R = 0.044 for 1407 observed reflections. N-Butyrylbenzamide, C11H13NO2 (III), Mr = 191.23, monoclinic, P2(1)/n, a = 8.270 (4), b = 12.600 (3), c = 10.459 (3) A, beta = 108.16 (3) degrees, V = 1040 (1) A3, Z = 4, Dx = 1.221 (1) g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 0.79 cm-1, F(000) = 408, T = 298 K, R = 0.038 for 1060 observed reflections. Compound (I) crystallizes in the Z,Z(trans-trans) conformation in chains linked by N-H...O hydrogen bonds. (I): N...O = 2.910 (2) A, NH...O = 170 (3) degrees. Compounds (II) and (III) crystallize in the E,Z(cis-trans) conformation and are linked by N-H...O hydrogen bonds forming eight-membered ring dimers. (II): N...O = 3.019 (4) A, NH...O = 167 (3) degrees and N...O = 2.982 (4) A, NH...O = 170 (3) degrees; (III): N...O = 2.990 (2) A, NH...O = 165 (2) degrees.