Crystal structure and Hirshfeld surface analysis of 2-methyl-3-nitro--[()-(5-nitro-thio-phen-2-yl)methyl-idene]aniline.

The title compound, CHNOS, synthesized by condensation of 5-nitro-thio-phene-2-carbaldehyde and 2-methyl-3-nitro-aniline, crystallizes in the ortho-rhom-bic space group 222. In the mol-ecule, the aromatic benzene and thio-phene rings are twisted with respect to each other, making a dihedral angle of 23.16 (7)°.

8-{(E)-[(4-Chloro-phen-yl)imino]-meth-yl}-1,1,7,7-tetra-methyl-1,2,3,5,6,7-hexa-hydro-pyrido[3,2,1-ij]quinolin-9-ol.

The title Schiff base, C23H27ClN2O adopts the phenol-imine tautomeric form, with an intra-molecular O-H⋯N hydrogen bond, which generates an S(6) ring motif. Three C atoms of the heterocyclic moiety of the hexa-hydro-pyrido-quinoline unit, as well as the two methyl groups bonded to one of these C atoms, are disordered over two set of sites, with anoccupancy ratio of 0.740 (4):0.

Combined experimental and theoretical approaches to the molecular structure of 4-(1-formylnaphthalen-2-yloxy)phthalonitrile.

The novel compound 4-(1-formylnaphthalen-2-yloxy)phthalonitrile, C(19)H(10)N(2)O(2,) has been synthesized and characterized by IR, UV-vis, NMR and X-ray single-crystal determination. The title compound, is built up from two planar groups (naphthalen and phthalonitrile), with a dihedral angle of 64.10(4)° between them.