organic compounds
In methyl 4-(4-chloroanilino)-3-nitrobenzoate, C14H11ClN2O4, (I), there is an intramolecular N-HO hydrogen bond and the intramolecular distances provide evidence for electronic polarization of the o-quinonoid type. The molecules are linked into sheets built from N-HO, C-HO and C-H(arene) hydrogen bonds, together with an aromatic - stacking interaction. The molecules of methyl 1-benzyl-2-(4-chlorophenyl)-1H-benzimidazole-5-carboxylate, C22H17ClN2O2, (II), are also linked into sheets, this time by a combination of C-H(arene) hydrogen bonds and aromatic - stacking interactions.
organic compounds
In the molecule of 4-(2-chlorophenyl)pyrrolo[1,2-a]quinoxaline, C17H11ClN2, (I), the bond lengths are consistent with electron delocalization in the two outer rings of the fused tricyclic system, with a localized double bond in the central ring. The molecules of (I) are linked into chains by a - stacking interaction. In (4RS)-4-(1,3-benzodioxol-6-yl)-4,5-dihydropyrrolo[1,2-a]quinoxaline, C18H14N2O2, (II), the central ring of the fused tricyclic system adopts a conformation intermediate between screw-boat and half-chair forms. A combination of N-HO and C-H(arene) hydrogen bonds links the molecules of (II) into a sheet. Comparisons are made with related compounds.
organic compounds
The molecules of both methyl 4-[2-(4-chlorobenzoyl)hydrazinyl]-3-nitrobenzoate, C15H12ClN3O5, (I), and methyl 4-[2-(2-fluorobenzoyl)hydrazinyl]-3-nitrobenzoate, C15H12FN3O5, (II), contain an intramolecular N-HO hydrogen bond, and both show electronic polarization in the nitrated aryl ring. In both compounds, molecules are linked by a combination of N-HO and C-HO hydrogen bonds to form sheets, which are built from R43(18) rings in (I) and from R44(28) rings in (II). In each of methyl 3-phenyl-1,2,4-benzotriazine-6-carboxylate, C15H11N3O2, (III), and methyl 3-(4-methylphenyl)-1,2,4-benzotriazine-6-carboxylate, C16H13N3O2, (IV), the benzotriazine unit shows naphthalene-type delocalization. There are no hydrogen bonds in the structures of compounds (III) and (IV), but in both compounds, the molecules are linked into chains by - stacking interactions involving the benzotriazine units. The mechanism of chain formation is the same in both (III) and (IV), and the different orientations of the two chains can be related to the approximate relationship between the unit-cell metrics for (III) and (IV).
organic compounds
In dibenzylammonium hydrogen maleate [or dibenzylammonium (2Z)-3-carboxyprop-2-enoate], C14H16N+·C4H3O4-, (I), the anion contains a fairly short and nearly linear O-HO hydrogen bond, with an O·O distance of 2.4603 (16) Å, but with the H atom clearly offset from the mid-point of the OO vector. The counter-ions in (I) are linked by two N-HO hydrogen bonds to form C22(6) chains and these chains are weakly linked into sheets by a C-HO hydrogen bond. Bis(dibenzylamino)methane, C29H30N2, (II), crystallizes with two independent molecules lying across twofold rotation axes in the space group C2/c, and the molecules are conformationally chiral; there are no direction-specific intermolecular interactions in the crystal structure of (II).