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1.  N′-[(E)-2-Chloro­benzyl­idene]thio­phene-2-carbohydrazide 
There are two independent mol­ecules in the asymmetric unit of the title compound, C12H9ClN2OS, a Schiff base derived from hydrazide, in which the dihedral angles between the thio­phene and benzene rings are 3.6 (3) and 7.3 (3)°. In the crystal, the two independent mol­ecules are arranged about an approximate non-crystallographic inversion center and are connected by two N—H⋯O hydrogen bonds. Weak C—H⋯Cl contacts are also present. Conversely, there are neither significant aromatic stacking inter­actions nor contacts involving S atoms.
doi:10.1107/S1600536813020850
PMCID: PMC3884466  PMID: 24427070
2.  (E)-N′-(4-Chloro­benzyl­idene)-1-benzofuran-2-carbohydrazide monohydrate 
The title compound, C16H11ClN2O2·H2O, exists in an E conformation with respect to the N=C bond. The benzofuran ring system forms a dihedral angle of 1.26 (4)° with the benzene ring. In the crystal, mol­ecules are linked via (N,C)—H⋯O bifurcated acceptor hydrogen bonds and (O,O,C)—H⋯O trifurcated acceptor hydrogen bonds, forming layers parallel to the bc plane.
doi:10.1107/S1600536812027523
PMCID: PMC3393970  PMID: 22798835
3.  (E)-N′-[3-(4-Chloro­benzo­yloxy)benzyl­idene]pyridine-4-carbohydrazide acetic acid monosolvate monohydrate 
In the Schiff base mol­ecule of the title compound, C20H14ClN3O3·CH3COOH·H2O, the central benzene ring makes dihedral angles of 36.26 (7) and 27.59 (8)°, respectively, with the terminal chloro­phenyl and pyridine rings. In the crystal, the three components are linked by O—H⋯O, N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds into a double-tape structure along the a axis.
doi:10.1107/S1600536812017369
PMCID: PMC3344622  PMID: 22590384
4.  (E)-N′-(5-Chloro-2-hydroxy­benzyl­idene)-4-(8-quinol­yloxy)butanohydrazide monohydrate 
The crystal of the title Schiff base compound, C20H18ClN3O3·H2O, was twinned by a twofold rotation about (100). The asymmetric unit contains two crystallographically independent mol­ecules with similar conformations, and two water mol­ecules. The C=N—N angles of 115.7 (6) and 116.2 (6)° are significantly smaller than the ideal value of 120° expected for sp 2-hybridized N atoms and the dihedral angles between the benzene ring and quinoline ring system in the two mol­ecules are 52.5 (7) and 53.9 (7)°. The mol­ecules aggregate via C—Cl⋯π and π–π inter­actions [centroid–centroid distances = 3.696 (5)–3.892 (5) Å] and weak C—H⋯O inter­actions as parallel sheets, which are further linked by water mol­ecules through N—H⋯O and O—H⋯O hydrogen bonds into a supra­molecular two-dimensional network.
doi:10.1107/S1600536809023733
PMCID: PMC2969487  PMID: 21582950
5.  N′-(2-Hydr­oxy-3-methoxy­benzyl­idene)-1,3-benzodioxole-5-carbohydrazide monohydrate 
Single crystals of the title compound, C16H14N2O5·H2O, were obtained from a condensation reaction of 1,3-benzodioxole-5-carbohydrazide and 3-methoxy­salicylaldehyde in a 95% ethanol solution. The asymmetric unit consists of a Schiff base mol­ecule, which assumes an E configuration with respect to the C=N bond, and a water mol­ecule of crystallization. The dihedral angle between the two substituted benzene rings is 12.7 (2)°. In the crystal structure, mol­ecules are linked through inter­molecular N—H⋯O and O—H⋯O hydrogen bonds, forming layers parallel to the bc plane.
doi:10.1107/S1600536808040117
PMCID: PMC2967948  PMID: 21581672
6.  4-[(2E)-2-(4-Chloro­benzyl­idene)hydrazinyl­idene]-1-methyl-1,4-dihydro­pyridine monohydrate 
In the title compound, C13H12ClN3·H2O, the organic mol­ecule is almost planar, with a dihedral angle of 3.22 (10)° between the benzene and pyridine rings. The crystal structure is stabilized by O—H⋯N and C—H⋯O hydrogen bonding and π–π stacking inter­actions [centroid–centroid distances = 3.630 (1) and 3.701 (1) Å].
doi:10.1107/S1600536810015709
PMCID: PMC2979526  PMID: 21579416
7.  (E)-N′-(2-Chloro­benzyl­idene)-1-methyl-4-nitro-1H-pyrrole-2-carbohydrazide 
In the title compound, C13H11ClN4O3, the phenyl and pyrrolyl ring are linked by an ac­yl–hydrazone (R 2C=N—N—CO—R) group, forming a slightly bent mol­ecule: the dihedral angle subtended by the the phenyl and pyrrolyl rings is 8.46 (12)°. In the crystal, the three-dimensional supra­molecular structure is assembled by N—H⋯O hydrogen bonding. Mol­ecular sheets are formed parallel to (101) in a herringbone arrangement by weak van der Waals inter­actions; weak π–π [centroid–centroid phen­yl–phenyl and pyrrol­yl–pyrrolyl distances of 3.7816 (3) and 3.8946 (2) Å, respectively] inter­actions occur between neighbouring sheets.
doi:10.1107/S1600536813034119
PMCID: PMC3914118  PMID: 24527025
8.  (E)-N′-(4-Chloro­benzyl­idene)-p-toluene­sulfonohydrazide 0.15-hydrate 
The asymmetric unit of the title compound, C14H13ClN2O2S·0.15H2O, a novel sulfonamide derivative, comprises two crystallographically independent mol­ecules (A and B) and a water mol­ecule of crystallization, which is partially occupied. One of the mol­ecules (B) is disordered over two positions (B and C) with refined site occupancies of 0.605 (10) and 0.395 (10). The dihedral angles between the two benzene rings in mol­ecules A, B and C are 67.8 (3), 74.6 (5) and 84.96 (11)°, respectively. In the crystal structure, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link the components of the asymmetric unit. The crystal structure is further stabilized by inter­molecular π–π inter­actions [centroid–centroid distances = 3.4518 (10)–3.5859 (10) Å].
doi:10.1107/S1600536809014512
PMCID: PMC2977795  PMID: 21583931
9.  (2E)-N′-[(E)-4-Chloro­benzyl­idene]-3-phenyl­prop-2-enohydrazide monohydrate 
The conformation about each of the imine and ethene bonds in the title hydrazide hydrate, C16H13ClN2O·H2O, is E. The hydrazide mol­ecule is approximately planar (r.m.s. deviation of the 20 non-H atoms = 0.172 Å). The most significant twist occurs about the ethene bond [C—C=C—C = 164.1 (5)°] and the dihedral angle formed between the benzene rings is 5.3 (2)°]. In the crystal, the presence of N—H⋯Ow and O—H⋯Oc (× 2; w = water and c = carbon­yl) hydrogen bonds leads to a supra­molecular array in the bc plane.
doi:10.1107/S160053681003388X
PMCID: PMC3007965  PMID: 21588739
10.  1-{2-[(4-Chloro­benzyl­idene)amino]phen­yl}-3-phenyl­thio­urea 
The asymmetric unit of the title compound, C20H16ClN3S, contains two independent mol­ecules, A and B. In mol­ecule A, the dihedral angles between the central benzene ring and the pendant chloro­benzene and phenyl rings are 6.37 (15) and 64.79 (15)°, respectively. The corresponding values in mol­ecule B are 28.21 (14) and 82.11 (16)°, respectively. Each mol­ecule features an intra­molecular N—H⋯N hydrogen bond, which generates an S(5) ring. In the crystal, mol­ecules A and B form dimers, being linked by two N—H⋯S hydrogen bonds with graph-set notation R 2 2(8).
doi:10.1107/S1600536812006228
PMCID: PMC3295530  PMID: 22412641
11.  N′-[(E)-2-Hy­droxy-5-iodo­benzyl­idene]furan-2-carbohydrazide monohydrate 
The organic mol­ecule of the title monohydrate, C12H9IN2O3·H2O, features a disordered furyl ring with the major component [site occupancy = 0.575 (18)] having the carbonyl O and furyl O atoms syn, and the other conformation having these atoms anti. The mol­ecule is slightly twisted with the dihedral angle between the benzene and furyl rings being 10.3 (6)° (major component). An intra­molecular O—H⋯N(imine) hydrogen bond is formed. In the crystal, the water mol­ecule accepts a hydrogen bond from an amine H atom, and forms two O—H⋯O(carbon­yl) hydrogen bonds, thereby linking three different carbohydrazide mol­ecules. The result is a supra­molecular layer parallel to (001). The closest contacts between layers are of the type I⋯I, at a distance of 3.6986 (6) Å.
doi:10.1107/S1600536811055826
PMCID: PMC3275173  PMID: 22347029
12.  Crystal structure of 2-[(E)-2-(2-chloro­benzyl­idene)hydrazin-1-yl]-4-phenyl-1,3-thia­zole 
The asymmetric unit of the title compound, C16H12ClN3S, contains two independent mol­ecules whose conformations differ primarily in the orientations of the phenyl and chloro­benzene rings with respect to the thia­zole ring. In the first mol­ecule, the dihedral angles are 3.0 (1) and 9.2 (1)°, respectively, for the phenyl ring and the chloro­benzene ring, while in the second mol­ecule, the corresponding angles are 18.6 (1) and 23.4 (1)°. In the crystal, the two independent mol­ecules are associated via complementary N—H⋯N hydrogen bonds into a dimer. These dimers are associated through weak C—H⋯Cl and C—H⋯S inter­actions into supra­molecular chains propagating along the a-axis direction.
doi:10.1107/S1600536814016298
PMCID: PMC4186150  PMID: 25309246
crystal structure; 1,3-thia­zole; hydrogen bonding; hydrogen-bonded dimers
13.  2′-(3-Hydroxy­benzyl­idene)pyrazine-2-carbohydrazide monohydrate 
The title compound, C12H10N4O2·H2O, was synthesized by the reaction of pyrazine-2-carboxylic acid hydrazide and 3-hydroxy­benzaldehyde in ethanol. In the crystal structure, the organic mol­ecules are linked into extended chains by inter­molecular N(amide)—H⋯O(hydr­oxy) hydrogen bonds. Additional hydrogen bonds between the water mol­ecule and three adjacent organic mol­ecules, as well as face-to-face π–π stacking inter­actions between the benzene and pyrazine rings [centroid-to-centroid separation = 3.669 (2) Å and offset = 1.362 Å], link the mol­ecules into a three-dimensional framework.
doi:10.1107/S1600536807062708
PMCID: PMC2915038  PMID: 21200959
14.  Bis{(E)-N′-[2,4-bis(trifluoro­meth­yl)benzyl­idene]isonicotinohydrazide} monohydrate 
The asymmetric unit of the title compound, 2C15H9F6N3O·H2O, contains two independent Schiff base mol­ecules and one water mol­ecule. Both Schiff base mol­ecules exist in an E configuration with respect to the C=N double bonds and the dihedral angles between the benzene and the pyridine rings in the two mol­ecules are 17.53 (12) and 20.62 (12)°. In the crystal structure, mol­ecules are linked by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds into infinite one-dimensional chains along the a axis. In addition, inter­molecular O—H⋯N, O—H⋯F, C—H⋯F and C—H⋯O hydrogen bonds further link these chains into a three-dimensional network. Weak π–π inter­actions with centroid–centroid distances in the range 3.6495 (17)–3.7092 (16) Å are also observed.
doi:10.1107/S1600536810025493
PMCID: PMC3007333  PMID: 21588249
15.  N′-(2-Chloro­benzyl­idene)benzo­hydrazide 
The asymmetric unit of the title compound, C14H11ClN2O, contains two independent mol­ecules. In one mol­ecule, the two aromatic rings form a dihedral angle of 45.94 (16)°, while in the second mol­ecule this angle is 58.48 (16)°. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into two crystallographically independent sets of chains propagating along [001].
doi:10.1107/S1600536809040331
PMCID: PMC2971129  PMID: 21578286
16.  N′-[(E)-1-(5-Chloro-2-hy­droxy­phen­yl)ethyl­idene]pyridine-3-carbohydrazide monohydrate 
In the title compound, C14H12ClN3O2·H2O, the benzene ring and the pyridine rings are oriented at a dihedral angle of 57.73 (12)° and an intra­molecular O—H⋯N hydrogen bond generates an S(6) ring. In the crystal, the water mol­ecule forms O—H⋯O and O—H⋯N hydrogen bonds to the organic mol­ecule, leading to chains containing R 4 4(16) loops. In addition, weak aromatic π–π stacking inter­actions between the centroids of pyridine rings [at distance of 3.864 (2) and 4.013 (2) Å] and C—H⋯π inter­actions occur.
doi:10.1107/S1600536810025213
PMCID: PMC3006986  PMID: 21588074
17.  (E)-N′-(2-Chloro­benzyl­idene)-3,5-di­hydroxy­benzohydrazide dihydrate 
In the Schiff base mol­ecule of the title compound, C14H11ClN2O3·2H2O, the benzene rings form a dihedral angle of 20.6 (1)°. The water molecules of crystallization are involved in the formation of a three-dimensional hydrogen-bonding network via O—H⋯O and N—H⋯O hydrogen bonds.
doi:10.1107/S1600536811042681
PMCID: PMC3247416  PMID: 22220034
18.  1-(2-Chloro­benzyl­idene)-2-(2,4-dinitro­phen­yl)hydrazine 
In the title compound, C13H9ClN4O4, there are two crystallographically independent mol­ecules in the asymmetric unit, which have very similar conformations. The C=N—N angles in each independent mol­ecule are 115.0 (2) and 116.6 (2)°, which are significantly smaller than the ideal value of 120° expected for sp 2-hybridized N atoms. This is probably a consequence of repulsion between the nitro­gen lone pairs and the adjacent N—N bonds. Two bifurcated intra­molecular N—H⋯O hydrogen bonds help to establish the mol­ecular conformation and consolidate the crystal packing.
doi:10.1107/S1600536808033357
PMCID: PMC2959777  PMID: 21580996
19.  (3E,5E)-1-Acryloyl-3,5-bis­(2-chloro­benzyl­idene)piperidin-4-one 
In the title compound, C22H17Cl2NO2, the asymmetric unit consists of two crystallographically independent mol­ecules and each piperidinone ring adopts an envelope conformation. The dihedral angles between the two chloro­benzene rings are 24.81 (10) and 19.15 (8)° in the two mol­ecules. In the crystal, mol­ecules are connected via weak inter­molecular C—H⋯O hydrogen bonds forming layers perpendicular to the a axis.
doi:10.1107/S1600536811015042
PMCID: PMC3089119  PMID: 21754526
20.  N′-(2-Hydr­oxy-5-chloro­benzyl­idene)-4-nitro­benzohydrazide methanol solvate 
The title compound, C14H10ClN3O4·CH4O, was synthesized from the reaction of 5-chloro­salicylaldehyde with 4-nitro­benzohydrazide in methanol. The Schiff base mol­ecule is nearly planar, with a dihedral angle of 9.1 (3)° between the two benzene rings. The methanol solvent mol­ecules are linked to the Schiff base mol­ecules by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming chains running parallel to the a axis.
doi:10.1107/S160053680800843X
PMCID: PMC2961199  PMID: 21202274
21.  2-(1H-1,2,3-Benzotriazol-1-yl)-N′-(2-chloro­benzyl­idene)acetohydrazide 
In the title compound, C15H12ClN5O, the mean planes of the benzotriazole and chloro­phenyl fragments form a dihedral angle of 70.8 (1)°. In the crystal, mol­ecules are linked into infinite chains along the a axis by N—H⋯O hydrogen bonds. Weak inter­molecular C—H⋯N hydrogen bonds further link these chains into layers parallel to the ab plane. The crystal studied was a racemic twin.
doi:10.1107/S1600536810050440
PMCID: PMC3050203  PMID: 21522757
22.  N′-(4-Chloro­benzyl­idene)furan-2-carbohydrazide monohydrate 
In the title compound, C12H9ClN2O2·H2O, the dihedral angle between the aromatic rings is 13.9 (2)° and an intra­molecular N—H⋯O hydrogen bond occurs. In the crystal structure, the components are linked by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds.
doi:10.1107/S1600536810005532
PMCID: PMC2983546  PMID: 21580384
23.  3-Chloro-N′-(3-eth­oxy-2-hy­droxy­benzyl­idene)benzohydrazide monohydrate 
In the title compound, C16H15ClN2O3·H2O, the water mol­ecule is linked to the Schiff base mol­ecule via an O—H⋯O hydrogen bond. In the Schiff base mol­ecule, an intramolecular O—H⋯N hydrogen bond occurs and the dihedral angle between the two benzene rings is 20.5 (5)°. In the crystal, the Schiff base and water mol­ecules are linked by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds, forming layers in the ab plane.
doi:10.1107/S160053681100122X
PMCID: PMC3051784  PMID: 21523054
24.  N′-[(E)-4-Chloro­benzyl­idene]-2-(4-isobutyl­phen­yl)propanohydrazide 
The asymmetric unit of title compound, C20H23ClN2O, consists of two crystallographically independent mol­ecules (A and B) in which the orientations of the 4-isobutyl­phenyl units are different. The isobutyl group of mol­ecule B is disordered over two positions with occupancies of 0.850 (5) and 0.150 (5). The dihedral angle between the two benzene rings is 88.70 (9)° in mol­ecule A and 89.38 (9)° in mol­ecule B. The independent mol­ecules are linked together into chains along [100] by N—H⋯O and C—H⋯O hydrogen bonds, and by C—H⋯π inter­actions. In the chain, N—H⋯O and C—H⋯O hydrogen bonds generate R 2 1(6) ring motifs. In addition, C—H⋯N hydrogen bonds are observed. The presence of pseudosymmetry in the structure suggests the higher symmetry space group Pbca but attempts to refine the structure in this space group resulted in high R (0.119) and wR (0.296) values.
doi:10.1107/S1600536809015906
PMCID: PMC2969596  PMID: 21583068
25.  (Z)-3-Diethyl­amino-6-({2-[(E)-4-(diethyl­amino)-2-hy­droxy­benzyl­idene­amino]-4,5-dimethyl­phen­yl}amino­methyl­idene)cyclo­hexa-2,4-dienone–5,5′-bis­(diethyl­amino)-2,2′-[4,5-dimethyl-o-phenyl­enebis(nitrilo­methyl­idyne)]diphenol 
The asymmetric unit of the title Schiff base compound, C30H38N4O2, comprises two crystallographically independent mol­ecules, A and B. The structure is non-merohedrally twinned with a refined BASF ratio of 0.219 (6):0.701 (6). Mol­ecule B shows both phenol–imine and keto–amine tautomeric forms in a single structure. The dihedral angles between the central ring and the two outer rings are 5.9 (3) and 48.4 (3)° in mol­ecule A, and 48.3 (3) and 6.9 (3)° in mol­ecule B. Strong intra­molecular O—H⋯N and N—H⋯O hydrogen bonds generate S(6) ring motifs. The crystal structure is further stabilized by inter­molecular C—H⋯O, C—H⋯π and π–π inter­actions [centroid–centroid distances = 3.870 (4)–3.871 (4) Å].
doi:10.1107/S1600536810045290
PMCID: PMC3011455  PMID: 21589416

Results 1-25 (308561)