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1.  2-{(E)-[(2Z)-2-(1,2-Di­hydro­phthalazin-1-yl­idene)hydrazinyl­idene]meth­yl}phenol 
The title compound, C15H12N4O, adopts an E conformation with respect to the azomethine bond and crystallizes in its hydrazinyl­idene tautomeric form. The dihedral angle between the ring systems is 15.98 (7)°. The phenol O—H group forms an intra­molecular O—H⋯N hydrogen bond. In the crystal, pairs of N—H⋯N and C—H⋯O hydrogen bonds link neighbouring mol­ecules into centrosymmetric dimers. These dimers are inter­connected by means of three types of π–π stacking inter­actions. One, with a centroid–centroid distance of 3.577 (1) Å [inter­planar separation = 3.4673 (6) Å], connects adjacent mol­ecules into centrosymmetric dimers. The other two inter­actions, on the outward facing sides of the dimers, are between phenol rings of neighboring mol­ecules [centroid–centroid separation = 3.7907 (13) Å and inter­planar separation = 3.5071 (8) Å], and between phthalazin units [centroid–centroid separation = 3.6001 (12) Å and inter­planar separation = 3.4891 (7) Å]. In combination, the π–π inter­actions lead to the formation of infinite layers with mol­ecules stacked along [0-11]. These layers are, in turn, connected with neighbouring layers through the N—H⋯N and C—H⋯O hydrogen bonds, yielding a three-dimensional supra­molecular architecture.
PMCID: PMC3790393  PMID: 24098212
2.  (3-Chloro­phen­yl)[(E)-2-(1,3-di­thio­lan-2-yl­idene)hydrazinyl­idene]methyl 3-chloro­benzoate 
In the title compound, C17H12Cl2N2O2S2, the di­thia­cyclo­pentane ring has an envelope conformation with one of the methyl­ene C atoms as the flap. The chloro­phenyl rings make a dihedral angle of 82.63 (7)°. In the crystal, π–π inter­actions between the benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.547 (2) Å] link the mol­ecules into inversion dimers. Weak non-classical C—H⋯X (X = O, N, Cl) inter­actions further consolidate the packing, forming a layer structure parallel to (110).
PMCID: PMC3648247  PMID: 23723867
3.  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].
PMCID: PMC2979526  PMID: 21579416
4.  (E)-[2-(1,3-Dithio­lan-2-yl­idene)hydrazinyl­idene](3-fluoro­phen­yl)methyl 3-fluoro­benzoate 
In the title compound, C17H12F2N2O2S2, the conformation of the dithia­cyclo­pentane ring is a half-chair, with a total puckering amplitude Q T = 0.460 (1) Å. π–π inter­actions [centroid–centroid distance = 3.585 (9) Å between the fluoro­phenyl rings of neighbouring mol­ecules] and C—H⋯N and C—H⋯O inter­actions help to stabilize the crystal structure and form ladders along the c axis.
PMCID: PMC3629619  PMID: 23634106
5.  2-(2-{[2-(4-Pyridylcarbon­yl)hydrazinyl­idene]meth­yl}phen­oxy)acetic acid 
In the title compound, C15H13N3O4, the pyridine and benzene rings are nearly perpendicular [dihedral angle = 84.24 (5)°]. In the crystal structure, classical O—H⋯N hydrogen bonding between the OH group of the carboxyl unit and a neighbouring pyridine ring N atom and N—H⋯O hydrogen bonding between the imine NH group and a neighbouring O atom of an acyl unit, together with complementary non-classical C—H⋯O hydrogen bonds between carboxyl O atoms and neighbouring CH groups, link the mol­ecules into a three-dimensional system.
PMCID: PMC2979532  PMID: 21579430
6.  4-{[2-(2,4-Dinitro­phen­yl)hydrazinyl­idene]meth­yl}phenol ethanol hemisolvate 
In the title compound, C13H10N4O5·0.5C2H5OH, the two benzene rings form a dihedral angle of 4.29 (9)°. The ethanol solvent mol­ecule was treated as disordered between two orientations related by symmetry (center of inversion), with occupancies fixed at 0.5. The crystal packing, stabilized by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds and π–π inter­actions [indicated by the short distance of 3.7299 (7) Å between the centroids of benzene rings from neighbouring mol­ecules], exhibits short inter­molecular O⋯O contacts of 2.8226 (3) Å.
PMCID: PMC3011783  PMID: 21589441
7.  Crystal structure of (Z)-ethyl 3-[2-(5-methyl-7-nitro-1H-indole-2-carbon­yl)hydrazinyl­idene]butano­ate 
The reaction of 5-methyl-7-nitro-1H-indole-2-carbohydrazide with ethyl aceto­acetate yielded the title mol­ecule, C16H18N4O5, in which the indole ring is almost planar, with the greatest deviation from the mean plane being 0.006 (2) Å. The nine atoms of the indole ring are almost perpendicular to the mean plane through the ethyl acetate group, as indicated by the dihedral angle of 87.02 (4)° between them. In the crystal, centrosymmetric supra­molecular dimers are formed via N—H⋯O hydrogen bonds and eight-membered amide {⋯HNCO}2 synthons. These are consolidated into a three-dimensional architecture by C—H⋯O contacts, and by π–π inter­actions between six-membered rings [inter-centroid distance = 3.499 (2) Å].
PMCID: PMC4555398  PMID: 26396904
crystal structure; conformation; hydrogen bonding
8.  4-{2-[2-(4-Chloro­benzyl­idene)hydrazinyl­idene]-3,6-dihydro-2H-1,3,4-thia­diazin-5-yl}-3-(4-meth­oxy­phen­yl)sydnone 
The title compound, C19H15ClN6O3S, exists in trans and cis configurations with respect to the acyclic C=N bonds. The 3,6-dihydro-2H-1,3,4-thia­diazine ring adopts a half-boat conformation. The sydnone ring is approximately planar [maximum deviation = 0.013 (1) Å] and forms dihedral angles of 34.76 (4) and 48.67 (4)° with the benzene rings. An intra­molecular C—H⋯O hydrogen bond stabilizes the mol­ecular structure and forms an S(6) ring motif. In the crystal packing, inter­molecular N—H⋯N hydrogen bonds link centrosymmetrically related mol­ecules into dimers, generating R 2 2(8) ring motifs. The dimers are then linked into a three-dimensional network by inter­molecular C—H⋯O and C—H⋯Cl hydrogen bonds, and by C—H⋯π inter­actions. Further stabilization is provided by π–π inter­actions involving the sydnone rings, with centroid–centroid separations of 3.4198 (5) Å.
PMCID: PMC3089192  PMID: 21754480
9.  4-{2-[2-(4-Chloro­benzyl­idene)hydrazinyl­idene]-3,6-dihydro-2H-1,3,4-thia­diazin-5-yl}-3-phenyl­sydnone 
The title compound, C18H13ClN6O2S, exists in trans and cis configurations with respect to the acyclic C=N bonds [C=N = 1.2837 (15) and 1.3000 (14) Å, respectively]. The 3,6-dihydro-2H-1,3,4-thia­diazine ring adopts a half-boat conformation. The sydnone ring is approximately planar [maximum deviation = 0.002 (1) Å] and forms dihedral angles of 50.45 (7) and 61.21 (6)° with the aromatic rings. In the crystal, inter­molecular N—H⋯N, C—H⋯Cl and C—H⋯S hydrogen bonds link the mol­ecules into layers parallel to ab plane. The crystal packing is stabilized by C—H⋯π inter­actions and further consolidated by π–π inter­actions involving the phenyl rings [centroid–centroid distance = 3.6306 (7) Å].
PMCID: PMC3089094  PMID: 21754481
10.  Methyl 2-meth­oxy-4-{[2-(4-nitro­phen­yl)hydrazinyl­idene]meth­yl}benzoate 
The mol­ecule of the title Schiff base compound, C16H15N3O5, obtained from a condensation reaction of 4-acet­oxy-3-meth­oxy­benzaldehyde and 4-nitro­phenyl­hydrazine, adopts an E geometry with respect to the C=N double bond. The mol­ecule is roughly planar, with the two benzene rings twisted slightly with respect to each other by a dihedral angle of 6.90 (9)°. In the crystal, inter­molecular N—H⋯O hydrogen bonds link centrosymmetrically related pairs of mol­ecules, forming dimers of R 2 2(22) graph-set motif. The dimers are further connected through slipped π–π inter­actions between symmetry-related benzene rings [centroid–centroid distance of 3.646 (1) Å, offset angle of 15.4°].
PMCID: PMC2983317  PMID: 21587632
11.  3-Chloro-4-[2-(4-chloro­benzyl­idene)hydrazinyl­idene]-1-methyl-3,4-dihydro-1H-2λ6,1-benzothia­zine-2,2-dione 
In the title compound, C16H13Cl2N3O2S, the dihedral angle between the aromatic rings is 6.62 (2)° and the C=N—N=C torsion angle is 176.2 (4)°. The thia­zine ring shows an envelope conformation, with the S atom displaced by 0.633 (6) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.037 Å). The Cl atom is an an axial conformation and is displaced by 2.015 (6) Å from the thia­zine ring plane. In the crystal, mol­ecules are linked by C—H⋯O inter­actions, generating a three-dimensional network. Very weak aromatic π–π stacking inter­actions [centroid–centroid separations = 3.928 (2) Å] are also observed.
PMCID: PMC3588526  PMID: 23476596
12.  rac-(3S,4Z)-3-Chloro-4-[2-(3-fluoro­benzyl­idene)hydrazinyl­idene]-1-methyl-3,4-dihydro-1H-2λ6,1-benzothia­zine-2,2-dione 
In the title compound, C16H13ClFN3O2S, the dihedral angle between the benzene rings is 4.47 (3)°. The conformation of the thia­zine ring is a half-chair and the Cl atom is in an axial orientation. In the crystal, mol­ecules are linked by C—H⋯F inter­actions, generating C(12) chains propagating in [011]. Aromatic π–π stacking inter­actions [centroid–centroid separations = 3.753 (2) and 3.758 (2) Å] also occur.
PMCID: PMC3379366  PMID: 22719564
13.  Methyl (2Z)-((2Z)-2-{(2E)-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinyl­idene}-4-oxo-3-phenyl-1,3-thia­zolidin-5-yl­idene)ethano­ate 
The asymmetric unit of the title compound, C21H19N3O3S, contains two independent mol­ecules. In one mol­ecule, the 1,3-thia­zolidine ring forms dihedral angles of 86.19 (8) and 8.37 (8)° with the phenyl and benzene rings, respectively. The corresponding dihedral angles in the other mol­ecule are 69.60 (7) and 14.08 (7)°. The dihedral angle between the phenyl and benzene rings is 84.70 (8)° in one mol­ecule and 69.62 (8)° in the other. In the crystal, mol­ecules pack in layers approximately parallel to (10-2). There are weak C—H⋯O hydrogen bonds within these layers. Further weak C—H⋯O hydrogen bonding occurs between the layers to form a three-dimensional network. A weak C—H⋯π inter­action is also observed.
PMCID: PMC3884445  PMID: 24427040
14.  Bis[N-(2-hy­droxy­eth­yl)-N-propyl­dithio­carbamato-κ2 S,S′]bis­(4-{[(pyridin-4-yl­methyl­idene)hydrazinyl­idene]meth­yl}pyridine-κN 1)cadmium 
The complete mol­ecule of the title compound, [Cd(C6H12NOS2)2(C12H10N4)2], is generated by crystallographic inversion symmetry. The distorted octa­hedral trans-N2S4 donor set for the Cd2+ ion is defined by two symmetrically S,S′-chelating dithio­carbamate anions and two pyridine N atoms derived from two monodentate 4-pyridine­aldazine (or 4-{[(pyridin-4-yl­methyl­idene)hydrazinyl­idene}meth­yl]pyridine) mol­ecules [dihedral angle between the aromatic rings = 17.33 (8)°]. In the crystal, mol­ecules are connected into a supra­molecular chain via O—H⋯N hydrogen bonds involving the 4-pyridine­aldazine N atoms not involved in coordination to cadmium. Weak C—H⋯O and C—H⋯N links consolidate the packing.
PMCID: PMC3052135  PMID: 21522253
15.  2-[2-(2-Carb­oxy­phen­yl)hydrazinyl­idene]-3-oxo-N-phenyl­butyramide 
In the title compound, C17H15N3O4, the mol­ecule is in the keto–hydrazone form. Intra­molecular N—H⋯O hydrogen bonds ensure that the mol­ecule is nearly planar (r.m.s. deviation of non-H atoms is 0.098 Å), with the two benzene rings forming a dihedral angle of 10.04 (2)°. In the crystal, inversion dimers are formed via pairs of O—H⋯O hydrogen bonds involving the –CO2H groups.
PMCID: PMC3239046  PMID: 22199894
16.  {4-Bromo-2-[(2-{(ethyl­sulfan­yl)[(2-oxido­benzyl­idene-κO)amino-κN]methyl­idene}hydrazinyl­idene-κN 1)meth­yl]phenolato-κO}(ethanol-κO)dioxido­uranium(VI) 
In the title complex, [U(C17H14BrN3O2S)O2(C2H5OH)], the UVI cation has a distorted penta­gonal–bipyramidal environment with the penta­gonal plane defined by two N and two O atoms of the tetra­dentate Schiff base ligand and the O atom of the ethanol mol­ecule. Two oxide O atoms occupy the axial positions. The azomethine C=N group and the Br atom are disordered over two positions in a 0.8356 (18):0.1644 (18) ratio. The ethyl­thiolyl group is disordered over three conformations in a 0.8356 (18):0.085 (6):0.079 (6) ratio, and the ethanol ligand is also disordered over three orientations in a 0.470 (16):0.277 (19):0.253 (18) ratio. In the crystal, mol­ecules form centrosymmetric dimers through hydrogen bonding between ethanol O—H donors and phenolate O-atom acceptors. Weak C—H⋯O inter­actions consolidate the crystal packing.
PMCID: PMC3772406  PMID: 24046549
17.  (E)-1-(4-Nitro­phen­yl)-2-(4-{[(E)-2-(4-nitro­phen­yl)hydrazinyl­idene]meth­yl}benzyl­idene)hydrazine dihydrate 
The 30 non-H atoms in title dihydrazine compound, C20H16N6O4·2H2O, are close to coplanar, the r.m.s. deviation for these atoms being 0.096 Å. The conformation about each of the C=N bonds is E, and the mol­ecule has non-crystallographic 2/m symmetry. The presence of O—H⋯O and N—H⋯O hydrogen bonding leads to a three-dimensional network in the crystal structure. A highly disordered solvent mol­ecule is present within a mol­ecular cavity defined by the organic and water mol­ecules. Its contribution to the electron density was removed from the observed data in the final cycles of refinement and the formula, molecular weight and density are given without taking into account the contribution of the solvent molecule.
PMCID: PMC2980149  PMID: 21580076
18.  Ethyl 3-[2-(p-tolyl­carbamothio­yl)hydrazinyl­idene]butano­ate 
The title compound, C14H19N3O2S, was obtained from a condensation reaction of N-(p-tol­yl)hydrazinecarbothio­amide and ethyl acetoacetate. The mol­ecule assumes an E configuration; the thio­semicarbazide and ester groups are located on the opposite sides of the C=N bond. The almost planar thio­semicarbazide unit (r.m.s. deviation = 0.0130 Å) is tilted at a dihedral angle of 49.54 (12)° with respect to the benzene ring. Inter­molecular N—H⋯N and N—H⋯S hydrogen bonding stabilizes the crystal structure. The eth­oxy group of the ester unit is disordered over two positions, with a site-occupancy ratio of 0.680 (10):0.320 (10).
PMCID: PMC3009117  PMID: 21589138
19.  4-[2-(Anthracen-9-yl­methyl­idene)hydrazinyl­idene]-3-chloro-1-methyl-3,4-dihydro-1H-2λ6,1-benzothia­zine-2,2-dione 
In the title compound, C24H18ClN3O2S, the dihedral angle between the benzene ring and the anthracene ring system is 41.10 (8)°. The thia­zine ring has a half-chair conformation and the Cl atom is in an axial orientation. In the crystal, mol­ecules are linked by C—H⋯O inter­actions, generating C(8) chains along [100]. A C—H⋯N short contact occurs in the mol­ecule, generating an S(6) ring.
PMCID: PMC3379367  PMID: 22719565
20.  (E)-4-{[2-(2-Furylcarbon­yl)hydrazinyl­idene]meth­yl}-2-meth­oxy­phenyl acetate 
The mol­ecule of the title Schiff base compound, C15H14N2O5, was obtained from a condensation reaction of 4-acet­oxy-3-meth­oxy­benzaldehyde and 2-furyl­carbonyl­hydrazide. In the mol­ecule, the furyl ring makes a dihedral angle of 14.63 (10)° with the benzene ring. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains along the b axis. Futhermore, weak C—H⋯O inter­actions connect the chains, forming corrugated layers parallel to (001). The dihedral angle between the rings is 14.63 (10)°.
PMCID: PMC3099912  PMID: 21754157
21.  Ethyl 2-[(2,4-difluoro­phen­yl)hydrazinyl­idene]-3-oxobutano­ate 
The asymmetric unit of the title compound, C12H12F2N2O3, contains two mol­ecules, both of which exist in an E conformation with respect to their C=N bonds [1.321 (6) and 1.310 (6) Å]. The mol­ecular conformations are supported by intra­molecular N—H⋯O hydrogen bonds, which generate S(6) rings. In the crystal, mol­ecules are linked by C—H⋯O and C—H⋯F hydrogen bonds into layers lying parallel to (001). The crystal studied was an inversion twin with a 0.58 (1):0.42 (1) domain ratio.
PMCID: PMC3275180  PMID: 22347036
22.  4-{[2-(2,4-Dinitro­phen­yl)hydrazinyl­idene](phen­yl)meth­yl}-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one ethanol monosolvate 
In the title compound, C23H18N6O5·C2H6O, all three benzene rings lie in an approximate plane [maximum deviation = 0.2688 (16) Å] that makes an angle of 53.56 (3)° with the plane of the pyrazolone ring. Intra­molecular N—H⋯O hydrogen bonds occur. In the crystal, the ethanol solvent mol­ecule links adjacent mol­ecules through N—H⋯O—H⋯O hydrogen bonds, leading to an infinite chain along the c-axis direction. The ethyl group of the ethanol solvent mol­ecule is disordered over two set of sites in a 0.762 (5):0.238 (5) ratio.
PMCID: PMC3588976  PMID: 23476212
23.  (2E)-4-(4-Bromo­phen­yl)-2-{(2Z)-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinyl­idene}-3-phenyl-2,3-di­hydro-1,3-thia­zole 
In the title compound, C24H20BrN3S, the di­hydro­thia­zole ring is approximately planar, with a maximum deviation of 0.008 (2) Å, and is twisted with respect to the 4-bromo­phenyl ring, the phenyl ring and methyl­phenyl ring, making dihedral angles of 47.96 (8), 59.52 (9) and 16.96 (9)°, respectively. In the crystal, weak C—H⋯π inter­actions link inversion-related mol­ecules into supra­molecular dimers.
PMCID: PMC3790424  PMID: 24098243
24.  rac-(6S)-6-Hy­droxy-6-{2-[2-(propan-2-yl­idene)hydrazinyl­idene]prop­yl}indolo[2,1-b]quinazolin-12(6H)-one 
The chiral title compound, C21H20N4O2, crystallizes as a racemic mixture. In the crystal, mol­ecules form centrosymmetric π-overlapping dimers [inter­planar distance = 3.338 (6) Å], which are further connected along the a axis forming centrosymmetric dimers via O—H⋯N hydrogen bonds. C—H⋯O inter­actions are also observed. The indolo[2,1-b]quinazoline group is somewhat bent, with a small dihedral angle of 6.3 (4)° between the plane of the quinazoline system and the plane of the benzene ring of the indole moiety. The C=N—N=C atoms of the azine group is oriented almost perpendicular [84.1 (2)°] to the mean plane of the quinazoline system.
PMCID: PMC3201358  PMID: 22065467
25.  6-Bromo-1-methyl-4-[2-(1-phenyl­ethyl­idene)hydrazinyl­idene]-3,4-dihydro-1H-2λ6,1-benzothia­zine-2,2-dione 
In the title compound, C17H16BrN3O2S, the dihedral angle between the aromatic rings is 1.24 (15)° and the C=N—N=C torsion angle is 167.7 (3)°. The conformation of the thia­zine ring is an envelope, with the S atom displaced by 0.805 (3) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.027 Å). In the crystal, C—H⋯O inter­actions link the mol­ecules into C(10) [010] chains. A weak C—H⋯π inter­action is also observed.
PMCID: PMC3569229  PMID: 23424452

Results 1-25 (213045)