The ten-membered fused ring of the title compound, C(12)H(10)N(2)O, is essentially planar in the two independent mol-ecules of the asymmetric unit (r.m.s. deviations = 0.012 and 0.015 Å).

In the title compound, C(14)H(11)N(3)O(2), the dihedral angle between the phenyl ring and the benzotriazole ring system is 76.80 (19)° and the mol-ecule has an L-shaped conformation. In the crystal, weak aromatic π-π stacking is observed, the closest centroid-centroid distance being 3.754 (2) Å.

The title compound, C(8)H(8)N(2)S, was prepared by the condensation of N-methyl-1,2-phenyl-enediamine and carbon disulfide. The crystal structure is stabilized by a C-H⋯π inter-action between a benzene H atom and the benzene ring of a neighbouring mol-ecule, and by inter-molecular N-H⋯S inter-actions.

In the title compound, C20H18N2P, the P atom is bonded to the two phenyl and imidazole groups, with an average P-C bond length of 1.828 (2) Å. The three C-P-C bond angles have values consistent with a tetra-hedral geometry around the P atom with the fourth site occupied by a H atom. Crystal packing is through van der Waals inter-actions.

In the title compound, C(16)H(13)NO, the mol-ecules are connected three-dimensionally through non-classical C-H⋯O and C-H⋯π inter-actions of 3.272 (3), 3.380 (3) and 3.382 (4) Å. Classical hydrogen bonds are not observed. The dihedral angle between the benzyl and quinolin-2(1H)-one mean planes is 87.15 (7)°

The title compound, C(8)H(7)N(3)O(2), a potential anti-tumour drug and an anti-oxidant agent, was studied in order to give more insight into structure-function relationships. The 1-methyl-benzimidazole unit of the mol-ecule was found to be exactly planar and the nitro group is inclined at an angle of 10.4 (2)° to the plane of the heterocycle. The bond lengths in the present derivative were anal...