ABSTRACT
In the crystal of the title Schiff base compound, C13H9ClN2O2, [CNBA; systematic name: (E)-N-(4-chloro-phen-yl)-1-(4-nitro-phen-yl)methanimine], the CNBA mol-ecule shows whole-mol-ecule disorder (occupancy ratio 0.65:0.35), with the disorder components related by a twofold rotation about the shorter axis of the mol-ecule. The aromatic rings are inclined to each other by 39.3â (5)° in the major component and by 35.7â (9)° in the minor component. In the crystal, C-Hâ¯O hydrogen bonds predominate in linking the major components, while weak C-Hâ¯Cl inter-actions predominate in linking the minor components. The result is the formation of corrugated layers lying parallel to the ac plane. The crystal packing was analysed using Hirshfeld surface analysis and compared with related structures.
ABSTRACT
The 4-chloro- [C(14)H(11)ClN(2)O(2), (I)], 4-bromo- [C(14)H(10)BrN(2)O(2), (II)] and 4-diethylamino- [C(18)H(21)N(3)O(2), (III)] derivatives of benzylidene-4-hydroxybenzohydrazide, all crystallize in the same space group (P2(1)/c), (I) and (II) also being isomorphous. In all three compounds, the conformation about the C=N bond is E. The molecules of (I) and (II) are relatively planar, with dihedral angles between the two benzene rings of 5.75 (12) and 9.81 (17)°, respectively. In (III), however, the same angle is 77.27 (9)°. In the crystal structures of (I) and (II), two-dimensional slab-like networks extending in the a and c directions are formed via N-H···O and O-H···O hydrogen bonds. The molecules stack head-to-tail via π-π interactions involving the aromatic rings [centroid-centroid distance = 3.7622 (14) Å in (I) and 3.8021 (19) Å in (II)]. In (III), undulating two-dimensional networks extending in the b and c directions are formed via N-H···O and O-H···O hydrogen bonds. The molecules stack head-to-head via π-π interactions involving inversion-related benzene rings [centroid-centroid distances = 3.6977 (12) and 3.8368 (11) Å].
Subject(s)
Benzylidene Compounds/chemistry , Ethylamines/chemistry , Hydrazines/chemistry , Crystallography, X-Ray , Hydrogen Bonding , Molecular Conformation , Molecular StructureABSTRACT
In the title compound, [ZnCl(2)(C(6)H(6)FN)(2)], the Zn(II) atom has a slightly distorted tetra-hedral geometry, being coordinated by the N atoms of two 4-fluoro-aniline mol-ecules and the two Cl(-) anions. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 89.96â (13)°. In the crystal, mol-ecules are linked via pairs of N-Hâ¯Cl hydrogen bonds, forming chains propagating along the b axis. These chains are in turn linked via a second pair of N-Hâ¯Cl hydrogen bonds, forming a two-dimensional network parallel to the ab plane. The title compound crystallizes in the space group Pca2(1) and exhibits weak second harmonic generation (SHG) properties.
ABSTRACT
The title compound, C(28)H(22)Cl(2)N(2)O(2), crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The two mol-ecules differ essentially in the orientation of the outer aromatic rings. These dihedral angles are 56.07â (13) and 27.62â (15)â Å for mol-ecules A and B, respectively. In the crystal, A mol-ecules are related as centrosymmetric pairs through a weak π-π inter-action [centroid-centroid distance = 3.6959â (15)â Å]. There are also a number of inter-molecular C-Hâ¯O, C-Hâ¯N and C-Hâ¯π inter-actions present.
