The title compound, C25H19N, adopts an E conformation about the C=N bond. The naphthalene ring system and the phenyl rings form dihedral angles 38.1 (1), 46.9 (8) and 48.5 (1)°, respectively, with the mean plane of the central enimino fragment. The crystal packing exhibits no directional close contacts.
In the title compound, C22H20N2O2S, the molecule adopts a twisted E configuration around the C=N bond. The two phenyl rings are twisted from each other, making a dihedral angle of 78.00 (12)°. The methyl-substituted benzene ring makes dihedral angles of 32.37 (14) and 69.70 (12)° with the two phenyl rings. In the crystal structure, molecules are linked into extended chains along the b axis through intermolecular N—H⋯O hydrogen bonds.
In the title compound, C21H16N2O2, the dihedral angles between the mean planes of the 4-nitrophenyl ring and the two phenyl rings are 57.3 (5) and 16.8 (6)°. The imine group displays a C—C—N—C torsion angle of −24.9 (3)°.
A series of N-(2-phenylethyl)nitroaniline derivatives is presented, demonstrating that modest changes in the functional groups cause significant differences in molecular conformation, intermolecular interactions and packing.
2,4-Dinitro-N-(2-phenylethyl)aniline, C14H13N3O4, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N—H⋯O hydrogen bond. The anti conformation about the ethyl C—C bond leads to the phenyl and aniline rings being essentially parallel. Molecules are linked into dimers by intermolecular N—H⋯O hydrogen bonds, such that each amine H atom participates in a three-centre interaction with two nitro O atoms. Though the dimers pack so that the arene rings of adjacent molecules are parallel, the rings are staggered and π–π interactions do not appear to be favoured. 4,6-Dinitro-N,N′-bis(2-phenylethyl)benzene-1,3-diamine, C22H22N4O4, (II), differs from (I) in the presence of a second 2-phenylethylamine group on the substituted ring. Compound (II) also crystallizes with one unique molecule in the asymmetric unit. Both amine groups are involved in intramolecular N—H⋯O hydrogen bonds with adjacent nitro groups. Although one ethyl group adopts an anti conformation as in (I), the other is gauche, with the result that the pendant phenyl rings are not parallel. The amine group that is part of the gauche conformation participates in a three-centre N—H⋯O hydrogen bond with the nitro group of a neighbouring molecule, leading to dimers as in (I). The other amine H atom does not form any intermolecular hydrogen bonds. The packing leads to separations of ca 3.4 Å of the parallel anti phenyl and aminobenzene rings. 2-Cyano-4-nitro-N-(2-phenylethyl)aniline, C15H13N3O2, (III), differs from (I) only in having a cyano group in place of the 2-nitro group. The absence of the adjacent nitro group eliminates the intramolecular N—H⋯O hydrogen bond. Molecules of (III) adopt the same anti conformation about the ethyl group as in (I), but crystallize in the higher-symmetry monoclinic space group P21/n. The molecules are linked into dimers via N—H⋯N amine–cyano hydrogen bonds, while the nitro groups are not involved in any N—H⋯O interactions. Owing to the different symmetry, the molecules pack in a herringbone pattern with fewer face-to-face interactions between the rings. The closest such interactions are about 3.5 Å between rings that are largely slipped past one another. 4-Methylsulfonyl-2-nitro-N-(2-phenylethyl)aniline, C15H16N2O4S, (IV), differs from (I) in having a methylsulfonyl group in place of the 4-nitro group. The intramolecular N—H⋯O hydrogen bond is present as in (I). However, unlike (I), the conformation about the ethyl group is gauche, so the two arene rings are nearly perpendicular rather than parallel. The packing is significantly different from the other three structures in that there are no intermolecular hydrogen bonds involving the N—H groups. The molecules are arranged in tetragonal columns running along the c axis, with the aniline rings mostly parallel and separated by ca 3.7 Å. Taken together, these structures demonstrate that modest changes in functional groups cause significant differences in molecular conformation, intermolecular interactions and packing.
crystal structure; N-(2-phenylethyl)nitroaniline derivatives; secondary amines; nitric oxide release agents
In the title compound, C22H16F3N, the C=N bond of the central imine group adopts an E conformation. The dihedral angles between the 2-(trifluoromethyl)phenyl ring and the benzene rings are 9.34 (1) and 68.8 (1)°. The imine group displays a C—C—N=C torsion angle of 41.6 (3)°. In the crystal, weak C—H⋯F hydrogen bonds link the molecules into chains parallel to the b-axis direction.
The molecular structure of the title compound, C26H18N4O6S·C2H6OS, shows an E conformation of the hydrazone double bond. The presence of a methylene group between the benzo[de]isoquinoline and benzenesulfonyl moieties allows the 4-nitrophenyl ring and the benzo[de]isoquinoline system to be parallel with respect to each other, so that the molecule adopts a U-shaped spatial conformation. The dihedral angle between mean planes of these aromatic groups is 4.4 (1)°. This special arrangement enables neighboring molecules to be intercalated, forming slipped π–π interactions [centroid–centroid distance = 3.535 (2) Å] between the 4-nitrophenyl and benzo[de]isoquinoline groups and point-to-face C—H⋯π interactions between the benzo[de]isoquinoline and benzenesulfonyl aromatic systems. In addition, the crystal packing also features an intermolecular N—H⋯O interaction involving the amine group and the dimethyl sulfoxide solvent molecule.
The title compound, C18H12N2, adopts an E conformation with the benzylidenemalononitrile and phenyl groups located on opposite sides of the C=C bond. The two phenyl rings are oriented at a dihedral angle of 62.49 (7)°.
The complete molecule of the title compound, C42H36N6O2, is generated by a crystallographic twofold axis with two C atoms of the central phenyl group lying on the axis. In the independent part of the molecule, one amino group is involved in an intramolecular N—H⋯O hydrogen bond, and the two adjacent phenyl rings are twisted from the plane of the pyrazolone ring with dihedral angles of 6.82 (3) and 88.32 (6)°. The crystal packing exhibits no classical intermolecular contacts.
The reaction of [CoIII(TPP)Cl] (TPP is the dianion of 5,10,15,20-tetraphenylporphyrin) with an excess of 4-nitroaniline in dichloromethane leads to the title compound, [CoIII(C44H28N4)(C6H6N2O2)2]Cl·CH2Cl2. The CoIII ion lies on an inversion centre and is octahedrally coordinated by two N atoms of the NH2 groups of the two 4-nitroaniline trans-axial ligands and four pyrrole N atoms of the porphyrin. The asymmetric unit contains one half of the [CoIII(TPP)(4-nitroaniline)2]+ ion complex, one chloride counter-ion (lying on a twofold rotation axis) and one half dichloromethane solvent molecule, where the C atom lies on a twofold rotation axis. The average equatorial Co—N(pyrrole) distance (Co—Np) is 1.982 (2) Å and the axial Co—N(4-nitroaniline) bond length is 2.006 (2) Å. The crystal packing is stabilized by an N—H⋯Cl hydrogen bond between the N atom of the amino group of the 4-nitroaniline axial ligand and the chloride counter-ion. The supramolecular architecture is further stabilized by weak C—H⋯π interactions.
crystal structure; cobalt(III) complex; 5,10,15,20-tetraphenylporphyrin ligand
The molecule of the title compound, C26H24N4O7S, adopts a trans conformation about the central N—N bond, presumably to minimize steric between the substituents on these two atoms. An intramolecular N—H⋯O hydrogen bond occurs. The phenyl ring is disordered over two sets of sites, with an occupancy ratio of 0.624 (8):0.376 (8). The azolidine ring is essentially planar [maximum deviation = 0.008 (5) Å] and makes a dihedral angle of 4.3 (2)° with the benzene ring and dihedral angles of 74.1 (3) and 69.1 (5)°, respectively, with the mean planes of the major and minor components of the disordered phenyl ring. The packing in the crystal is aided by the formation of several weak C—H⋯O and C—H⋯N interactions.
There are two crystallographically independent molecules in the asymmetric unit of the title compound, C14H11ClN4O4, with the same E conformation about the C=N double bond. The molecules are approximately planar, with a dihedral angle between the benzene rings of 10.24 (12)° in one molecule and 4.73 (12)° in the other. In both molecules, the ortho-nitro groups of the 2,4-dinitrophenyl units are coplanar to their bound benzene rings, whereas the para-nitro groups are slightly twisted. In each molecule, intramolecular N—H⋯O hydrogen bonds generate S(6) ring motifs. In the crystal, molecules are linked by weak C—H⋯O interactions into sheets parallel to the (-102) plane. These sheets are stacked by π–π interactions, with centroid–centroid distances of 3.7008 (14) and 3.7459 (14) Å. A Cl⋯O short contact [3.111 (2) Å] is observed.
The zwitterionic title compound, C16H12N2O3, was obtained as a result of the condensation of 5-aminosalicylic acid and 1H-indole-3-carbaldehyde. The whole molecule is roughly planar: the 4-hydroxyanilinic group and the 1H-indole-3-carbaldehyde moieties are only slightly twisted, making a dihedral angle of 7.77 (11)°, whereas, the carboxylate group makes a dihedral angle of 3.34 (45)° with the parent 4-hydroxyanilinic group. S(6) ring motifs are formed due to intramolecular O—H⋯O hydrogen bonding. In the crystal, intermolecular N—H⋯O and C—H⋯O hydrogen bonds build up pseudo-rings with R
1(7) and R
2(14) ring motifs. These pseudo-dimers are further linked by N—H⋯O hydrogen bonds into a chain extending along . C—H⋯π interactions also occur, along with offset π–π interactions between the anilinic phenyl and the heterocyclic five-membered rings with a centroid–centroid distance of 3.5716 (19) Å.
In the title molecule, C25H21N5O3S, the triazole ring forms dihedral angles of 21.4 (2), 61.4 (2) and 102.4 (2)° with the nitrophenyl and two phenyl rings, respectively. In the crystal, weak C—H⋯O hydrogen bonds and π–π interactions between the benzene rings from neighbouring molecules [with a centroid–centroid distance of 3.571 (3) Å] consolidate the crystal packing.
The title compound, C16H13NO3, crystallizes with two independent molecules (A and B) in the asymmetric unit. The dihedral angle between the mean planes of the 4-methylphenyl and 3-nitrophenyl groups is 4.0 (3)° in molecule A and 16.2 (7)° in molecule B. Intermolecular C—H⋯O hydrogen bonding involving the O atoms of the 3-nitrophenyl group of both independent molecules link the molecules into layers approximately parallel to the (110) plane. The layers are held together by π–π stacking interactions between the 4-methylphenyl ring of molecule A and the 3-nitrophenyl ring of molecule B of the adjacent layer, with the distance between the centroids of interacting rings being 3.6987 (7) Å.
In the title compound, C25H21N5O3S·CH2Cl2, the dichloromethane solvent molecule is disordered over four positions, with an occupancy ratio of 0.271 (3):0.3884 (18):0.298 (2):0.0424 (15). The 1,2,4-triazole ring makes dihedral angles of 47.3 (2)/87.3 (2) and 3.6 (2)° with the phenyl and nitrophenyl rings, respectively. An intramolecular C—H⋯S hydrogen bond results in the formation of an almost planar six-membered ring [r.m.s. derivation = 0.0051 (2) Å]. Intermolecular C—H⋯O hydrogen bonding consolidates the structure.
The title compound, 2C17H13F3N3O+·SO4
2−·2H2O, crystallizes with four independent cations (A, B, C and D) in the asymmetric unit, which is composed of two groups of two cations, one anion and two water molecules (Z′ = 2). The dihedral angle between the mean planes of the 4-hydroxyphenyl and quinolinium groups is 8.9 (7)° in A, 30.1 (6)° in B, 28.8 (8)° in C and 12.8 (1)° in D. The crystal packing is stabilized by intermolecular O—H⋯O and N—H⋯O hydrogen bonding between H atoms from 4-hydroxyphenyl O atoms and the O atoms of nearby water molecules and sulfate anions, as well as H atoms from the N atom of the hydrazino group to O atoms of neighboring sulfate anions, linking the components into chains with the 4-hydroxyphenyl and quinolinium rings parallel to the (011) plane. There is also an extensive array of intermolecular hydrogen bonds between water molecules themselves and with sulfate O atoms, as well as hydrogen-bond interactions between H atoms from the hydrazino group and sulfate O atoms. In addition, intermolecular π–π stacking interactions occur between nearby 4-hydroxyphenyl and quinolinium groups, with distances between the centroids of interacting rings in the range 3.4140 (9)–3.9659 (9) Å.
The title compounds are the 3-ethyl, (I), and 3-isopropyl, (II), derivatives of (1-methyl-2,6-diphenylpiperidin-4-ylidene)amino phenyl carbonate. The main difference in the conformation of the two compounds is the angle of inclination of the phenoxycarbonyl ring with respect to the piperidine ring mean plane, with a dihedral angle of 2.05 (8)° in (I) and 45.24 (13)° in (II).
In the title compounds, C27H28N2O3, (I), and C28H30N2O3, (II), the conformation about the C=N bond is E. The piperidine rings adopt chair conformations with the attached phenyl rings almost normal to their mean planes, the dihedral angles being 85.82 (8) and 85.84 (7)° in (I), and 87.98 (12) and 86.42 (13)° in (II). The phenyl rings are inclined to one another by 52.87 (8)° in (I) and by 60.51 (14)° in (II). The main difference in the conformation of the two compounds is the angle of inclination of the phenoxycarbonyl ring to the piperidine ring mean plane. In (I), these two planes are almost coplanar, with a dihedral angle of 2.05 (8)°, while in (II), this angle is 45.24 (13)°. In the crystal of (I), molecules are linked by C—H⋯O hydrogen bonds, forming inversion dimers with R
2(14) loops. The dimers are linked via C—H⋯π interactions forming a three-dimensional network. In the crystal of (II), there are no significant intermolecular interactions present.
crystal structure; piperidine; oxime; 2,6-diphenylpiperidine
There are two crystallographically independent molecules (A and B) in the asymmetric unit of the title compound, C25H22N4O2S, with almost identical molecular conformations. The hydroxyphenyl ring plane and the 1,2,4-triazole ring form dihedral angles of 17.1 (2) and 7.4 (2)° in A and B, respectively. The dihedral angles between 1,2,4-triazole ring and the other two phenyl rings are 89.6 (3) and 83.3 (2)° in molecule A, and 89.2 (3) and 82.2 (2)° in molecule B. One intramolecular O—H⋯N hydrogen bond is present in each molecule. Weak intermolecular C—H⋯O hydrogen bonds consolidate the crystal packing.
In the title compound, C19H18N4O4, the nitrophenyl and phenyl rings are twisted by 67.0 (6) and 37.4 (4)°, respectively, with respect to the pyrazole ring plane [maximum deviation = 0.0042 (16) Å]. The dihedral angle between the mean planes of the phenyl rings is 59.3 (3)°. The amide group, with a C—N—C—C torsion angle of 177.54 (13)°, is twisted away from the plane of the pyrazole ring in an antiperiplanar conformation. In the crystal, N—H⋯O hydrogen bonds involving the carbonyl group on the pyrazole ring and the amide group, together with weak C—H⋯O interactions forming R
2(10) graph-set motifs, link the molecules into chains along . Additional weak C—H⋯O interactions involving the nitrophenyl rings further link the molecules along , also forming R
2(10) graph-set motifs, thereby generating (010) layers.
The title compound, C15H16F3NO4, is an N-substituted derivative of ortho-trifluoromethylaniline featuring a twofold Michael system. The least-squares planes defined by the atoms of the phenyl ring and the atoms of the Michael system enclose an angle of 15.52 (5)°. Apart from classical intramolecular N—H⋯O and N—H⋯F hydrogen bonds, intermolecular C—H⋯O contacts are observed, the latter connecting the molecules into chains along . The shortest intercentroid distance between two aromatic systems is 3.6875 (9) Å.
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].
The configuration about each C=N bond in the title compound, C22H20N4O3S, is E. While to a first approximation the phenylhydrazin-1-ylidene and benzohydrazide residues are coplanar, in part due to the presence of an intramolecular N—H⋯N hydrogen bond, significant twists are evident in the orientations of the hydrazine [N—N—C—C torsion angle = −170.74 (11)°] and benzoyl benzene [N—C—C—C = −21.72 (18)°] rings. The sulfonyl benzene ring occupies a position almost normal to the rest of the molecule [C—S—C—N = −92.28 (10)°]. Centrosymmetric aggregates mediated by pairs of hydrazide–sulfonyl N—H⋯O hydrogen bonds are the predominant packing motif in the crystal. These are connected into linear supramolecular chains via C—H⋯O interactions which are, in turn, linked into layers in the ac plane via C—H⋯π interactions. Connections between layers along the b-axis direction are of the π–π type and occur between centrosymmetrically related hydrazine-bound benzene rings [centroid–centroid separation = 3.7425 (9) Å].
The title compound, C15H13N3O2S2, was obtained from a condensation reaction of benzyl dithiocarbazate and 2-nitrobenzaldehyde. In the molecule, the nearly planar dithiocarbazate fragment [r.m.s deviation = 0.0264 Å] is oriented at dihedral angles of 7.25 (17) and 74.09 (9)°with respect to the two benzene rings. The nitro group is twisted by a dihedral angle of 22.4 (7)° to the attached benzene ring. The nitrobenzene ring and dithiocarbazate fragment are located on the opposite sides of the C=N bond, showing an E configuration. In the crystal, molecules are linked via intermolecular N—H⋯S hydrogen bonds, forming centrosymmetric supramolecular dimers. Weak C—H⋯π interaction is also observed in the crystal structure.
In the title compound, C17H19N5O5, obtained from the condensation reaction of 4-diethylamino-2-hydroxybenzaldehyde and 2,4-dinitrophenylhydrazine, the two benzene rings are twisted by a dihedral angle of 1.75 (12)°. The nitro groups are slightly twisted with the respect to the benzene ring to which they are attached, making dihedral angles of 8.20 (15) and 5.78 (15)°. An intramolecular O—H⋯N hydrogen bond occurs. In the crystal, molecules are linked by pairs of intermolecular N—H⋯O hydrogen bonds, forming dimers through R
2(12) rings. These dimers are further linked by C—H⋯O and C—H⋯π and weak slipped π–π interactions [centroid–centroid distance = 3.743 (2)Å]. One of the ethyl groups is disordered over two positions, with occupancy factors in the ratio 0.72:0.28.
In the title compound, C15H15N5O2S2, the phenyl rings make dihedral angles of 4.03 (4) and 9.77 (5)° with the plane defined by the central N—N—C—N—N atoms (r.m.s. deviation = 0.010 Å). The C—S—C—C torsion angles of the methylsulfanyl groups with their respective phenyl rings are −7.47 (13) and −72.07 (13)°. The shortest centroid–centroid distance of 3.707 Å occurs between the two π-systems N—N—C—N—N and the benzene ring in the diazene 1-position. The H atom bound to the N atom is involved in intramolecular N—H⋯N and N—H⋯S contacts, while the nitro O atoms are involved in intermolecular C—H⋯O contacts.