(E)-1-(2,4-Dinitro-phen-yl)-2-[1-(3-fluoro-phen-yl)ethyl-idene]hydrazine.

The mol-ecule of the title hydrazone derivative, C(14)H(11)FN(4)O(4), is nearly planar, with a dihedral angle between the benzene rings of 3.71 (7)°. The central ethyl-idenehydrazine N-N=C-C plane makes dihedral angles of 5.

(1E,2E)-1,2-Bis[1-(3-nitro-phen-yl)ethyl-idene]hydrazine.

The asymmetric unit of the title compound, C(16)H(14)N(4)O(4), contains one half-mol-ecule of (nitro-phen-yl)ethanimine and the complete mol-ecule is generated by a crystallographic inversion centre. The mol-ecule has an E conformation with respect to each C=N double bond. The central C=N-N=C plane is twisted from the benzene rings with a dihedral angle of 24.

(E)-1-(2,4-Dinitro-phen-yl)-2-[1-(2-nitro-phen-yl)ethyl-idene]hydrazine.

The title compound, C(14)H(11)N(5)O(6), was obtained from the condensation reaction of 2,4-dinitro-phenyl-hydrazine and 2-nitro-acetophenone. The mol-ecule displays an E conformation about the C=N double bond and an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. The dihedral angle between the benzene rings is 7.

(E)-1-[1-(2-Chloro-phen-yl)ethyl-idene]-2-(2,4-dinitro-phen-yl)hydrazine.

The title mol-ecule, C(14)H(11)ClN(4)O(4), is in an E configuration and is twisted with the dihedral angle between the two benzene rings being 38.48 (8)°. The ethyl-idenehydrazine plane makes dihedral angles of 6.

(1E,2E)-1,2-Bis[1-(3-chloro-phen-yl)ethyl-idene]hydrazine.

The title mol-ecule, C(16)H(14)Cl(2)N(2), lies on an inversion center. The dihedral angle between the symmetry-related benzene rings is 0.02 (11)°.

(E)-1-(2,4-Dinitro-phen-yl)-2-[1-(2-meth-oxy-phen-yl)ethyl-idene]hydrazine.

The mol-ecule of the title compound, C(15)H(14)N(4)O(5), is in an E conformation with respect to the C=N double bond and the dihedral angle between the two benzene rings is 37.83 (7)°. The ethyl-idenehydrazine plane makes dihedral angles of 4.

(1E,1'E)-4,4'-[1,1'-(Hydrazine-1,2-diyl-idene)bis-(ethan-1-yl-1-yl-idene)]diphenol dihydrate.

The asymmetric unit of the title compound, C(16)H(16)N(2)O(2)·2H(2)O, contains one half-mol-ecule of diphenol and one water mol-ecule. The complete diphenol mol-ecule is generated by a crystallographic inversion centre. In the mol-ecule, the central C(meth-yl)-C=N-N=C-C(meth-yl) plane makes a dihedral angle of 8.

(E,E)-1,2-Bis(2,4,5-trimeth-oxy-benzyl-idene)hydrazine.

The asymmetric unit of the title compound, C(20)H(24)N(2)O(6), contains one half-mol-ecule, the complete mol-ecule being generated by a crystallographic inversion centre. The mol-ecule is nearly planar with a dihedral angle between the two benzene rings of 0.03 (4)° and the central C/N/N/C plane making a dihedral angle of 8.

(E)-1-(2,4-Dinitro-phen-yl)-2-[1-(thio-phen-2-yl)ethyl-idene]hydrazine.

The mol-ecule of the title compound, C(12)H(10)N(4)O(4)S, is slightly twisted, with a dihedral angle of 8.23 (9)° between the benzene and thio-phene rings. One nitro group is co-planar [O-N-C-C torsion angles = -0.

(1E,2E)-1,2-Bis[1-(2-methoxy-phen-yl)ethyl-idene]hydrazine.

There are two crystallographically independent mol-ecules in the asymmetric unit of the title compound, C(18)H(20)N(2)O(2). The two mol-ecules exist in an E,E configuration with respect to the two C=N double bonds. The dihedral angles between the two benzene rings in each mol-ecule are 16.

(E,E)-1,2-Bis(2,4,6-trimeth-oxy-benzyl-idene)hydrazine.

The title mol-ecule, C(20)H(24)N(2)O(6), lies on an inversion centre. All non-H atoms are essentially coplanar, with an r.m.

(E,E)-1,2-Bis[1-(2-bromo-phen-yl)ethyl-idene]hydrazine.

In the title compound, C(16)H(14)Br(2)N(2), the complete molecule is generated by a crystallographic twofold axis. The dihedral angle between the two benzene rings is 35.28 (8)° and that between the best planes of two ethyl-idinehydrazine N-N=C-Me units is 87.

(E)-4-[2-(4-Eth-oxy-phen-yl)ethen-yl]-1-methyl-pyridinium 4-bromo-benzene-sulfonate methanol hemisolvate.

In the title compound, C(16)H(18)NO(+)·C(6)H(4)BrO(3)S(-)·0.5CH(3)OH, the cation exists in the E configuration and the whole mol-ecule of the cation, except for the O atom of the eth-oxy group, is disordered with a site-occupancy ratio of 0.695 (5):0.

(E)-4-[4-(Dimethyl-amino)styr-yl]-1-methyl-pyridinium 4-bromo-benzene-sulfonate.

In the title compound, C(16)H(19)N(2) (+)·C(6)H(4)BrO(3)S(-), the cation is nearly planar, with a dihedral angle of 3.19 (15)° between the pyridinium and the dimethylaminophenyl rings, and exists in the trans configuration. In the crystal packing, the cations and anions are linked into chains parallel to the c axis.