Browsing by Author "Karvembu, R"
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Item 1-[3-({[bis(2-methylpropyl)carbamothioyl]amino}carbonyl)benzoyl]-3, 3-bis(2-methylpropyl)thiourea(International Union of Crystallography, 2013-08-03) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.The title compound, C26H42N4O 2S2, adopts a shallow U-shape as both pendant arms of the 1,3-substituted benzene ring are orientated in the same direction. The thione S atoms lie to the same side of the benzene ring and the carbonyl O atoms to the other. The most prominent feature of the crystal packing is the formation of inversion dimers mediated by N - H⋯S hydrogen bonds. One of the 2-methylpropyl groups is statistically disordered over two positions. © 2013 Selvakumaran et al.Item 1-Benzoyl-3,3-bis(propan-2-yl)thiourea(International Union of Crystallography, 2010-07-24) Gunasekaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.Two independent thiourea derivatives comprise the asymmetric unit of the title compound, C14H20N2OS. The major difference between the mol-ecules relates to a twist in the relative orientation of the benzene rings [torsion angles = 4.5 (2) and -19.9 (2)° for the two independent mol-ecules]. The thio-carbonyl and carbonyl groups lie to opposite sides of the mol-ecule as there are twists about the central N - S bond [torsion angles = 83.90 (15) and 81.77 (15)°]. Supra-molecular chains extending parallel to [101] with a stepped topology and mediated by N - H⋯O hydrogen bonding feature in the crystal structure. C - H⋯O and C - H⋯π inter-actions are also present.Item 1-Benzoyl-3,3-bis-(2-methylpropyl)thiourea(International Union of Crystallography, 2011-02-12) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R.T.The title compound, C16H24N2OS, is twisted about the central N(H) - C bond with the C - N - C - S torsion angle being 119.6 (3)°. The carbonyl O and thione S atoms are directed to opposite sides of the molecule, a conformation that allows for the formation of a linear supramolecular chain comprising alternating eight-membered {⋯HNCS} 2 and 14-membered {⋯HCNCNCO}2 synthons.Item 1-Benzoyl-3,3-dibutylthiourea(International Union of Crystallography, 2010-09-25) Gunasekaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.The title molecule, C16H24N2OS, is twisted about the central N(H) - C bond with a C - N(H) - C - N torsion angle of -62.67 (15)°. The carbonyl group is twisted out of the plane of the benzene ring, forming a C - C - C=O torsion angle of -25.06 (17)°. In the crystal, molecules related by centres of symmetry are linked by pairs of inter-molecular N - H⋯S hydrogen bonds, forming eight-membered {⋯HNCS}2 synthons. These are further connected by weak via C - H⋯O contacts, forming a two-dimensional array in the bc plane.Item 1-Benzoyl-3-methyl-3-pentylthiourea(International Union of Crystallography, 2011-04-16) Gunasekaran, N; Jerome, P; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.Two independent molecules comprise the asymmetric unit of the title compound, C14H20N2OS. These differ in the relative orientations of the pentyl chains [C-C-C-C torsion angles = 176.7 (3) and 176.4 (3)°]. Significant twists are evident in each molecule, the dihedral angles formed between the thiourea and amide residues being 53.47 (17) and 55.81 (17)°. In the crystal, each molecule self-associates via a centrosymmetric eight-membered {⋯HNC S}2 synthon, and these are connected into a supramolecular chain along [110] via C-H⋯O contacts. Disorder is noted for one of the independent molecules in that two orientations (50:50) were resolved for its benzene ring.Item 3-({[Bis(2-methylpropyl)carbamothioyl]amino}carbonyl)benzamide(International Union of Crystallography, 2013-06-29) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.In the title compound, C17H25N3O2S, the terminal and central amide groups are, respectively, twisted and coplanar with the attached benzene ring [O - C - C - C torsion angles = 22.7 (3) and 5.4 (3)°]. In the central part of the molecule, the amide and thioamide residues are approximately perpendicular [C - N - C - S torsion angle = -104.98 (18)°]. Supramolecular layers with a zigzag topology are formed in the crystal packing by N - H...O, N - H...S and C - H...O interactions; these stack along c, being separated by hydrophobic interactions.Item 3-Benzoyl-1,1-dibenzylthiourea(International Union of Crystallography, 2010-09-18) Gunasekaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.Two independent thio-urea molecules comprise the asymmetric unit of the title compound, C22H20N2OS. The central N-C(=S)N(H)C(=O) atoms in each molecule are virtually superimposable and each is twisted [C - N - C - S torsion angles = 121.3 (3) and -62.3 (4)°]. The molecules differ only in terms of the relative orientations of the benzyl benzene rings [major difference between the C - N - C - C torsion angles of -146.6 (3) and -132.9 (3)°]. The presence of N - H⋯S hydrogen bonding leads to the formation of supra-molecular chains along the a axis. These are consolidated in the crystal packing by C - H⋯O interactions. The crystal was found to be a combined non-merohedral and racemic twin (twin law 1̄00/01̄0/001), with the fractional contribution of the minor components being approximately 9 and 28%.Item 3-Benzoyl-1-(2-methoxyphenyl)thiourea(International Union of Crystallography, 2012-11-03) Selvakumaran, N; Sheeba, M. Mary; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.In the title compound, C15H14N2O2S, the central C2N2OS moiety is planar (r.m.s. deviation of fitted atoms = 0.0336 Å). This is ascribed to the formation of an S(6) loop stabilized by an intramolecular N-H⋯O hydrogen bond; additional intramolecular N-H⋯O and C-H⋯S contacts are also noted. The dihedral angles between the central unit and the phenyl and benzene rings are 23.79 (7) and 29.52 (5)°, respectively. The thione S and ketone O atoms are mutually anti, as are the N-H H atoms; the O atoms lie to the same side of the molecule. Centrosymmetric eight-membered {⋯HNC=S}2 synthons feature in the crystal packing. The resulting inversion dimers stack along the a axis and are connected into a three-dimensional structure by C-H⋯O and C-H⋯π interactions.Item 3-{[(Dibenzylcarbamothioyl)amino]carbonyl}benzamide(International Union of Crystallography, 2013-06-29) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.Two independent molecules with quite similar conformations, A and B, comprise the asymmetric unit of the title compound, C23H21N3O2S. The terminal amide substituent is coplanar with the attached benzene ring [the O - C - C - C torsion angles are 174.0 (2) (A) and 6.3 (3)° (B)]. In the same way, the central amide group [C - C - C - O = 7.8 (3) (A) and 11.5 (3)° (B)] is approximately coplanar with the ring to which it is attached. A major twist is noted between the amide and adjacent thioamide residues [C - N - C - S = -109.29 (19) (A) and -112.29 (19)° (B)]. In the crystal, supramolecular chains along [100] are formed by N - H...O and N - H...S hydrogen bonding. These are connected into a three-dimensional architecture by C - H...π and π-π interactions [inter-centroid distance = 3.9157 (12) Å].Item {4-Bromo-2-[(2-sulfidophenyl)iminomethyl]phenolato-k3 S,N,O}(triphenylphosphane-kP)nickel(II)(International Union of Crystallography, 2011-03-12) Muthu Tamizh, M.; Karvembu, R; Varghese, B; Tiekink, Edward R. T.The NiII atom in the title complex, [Ni(C13H 8BrNOS)(C18H15P)], is coordinated by the N, O and S atoms of he dianionic tridentate ligand, and its square-planar geometry is completed by a phosphane P atom. The dihedral angle between the aromatic rings in the 4-bromo-2-[(2-sulfidohenyl)imino-meth-yl]phenolate ligand is 2.01 (14)°. The most prominent feature of the packing is the presence of supramolecular chains aligned along the a axis, mediated by C - H⋯S interactions.Item Bis(3-benzoyl-1,1-disecbutyl-thioureato- 2 O,S)palladium(II)(International Union of Crystallography, 2011-09-17) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.The complex molecule of the title complex, [Pd(C 16H 23N 2OS) 2], is completed by crystallographic twofold symmetry with the metal atom lying on the rotation axis. The Pd II atom exists within a slightly distorted squareplanar geometry defined by a cis-O 2S 2 donor set. The dihedral angle formed between the mean planes of the symmetry-related six-membered chelate rings is 12.88 (7)° and the bond lengths within the rings are indicative of significant electron delocalization. In the crystal, molecules aggregate into dimers linked by four C-H⋯O interactions.Item Crystal structure of (2E)-N-methyl-2-(2-oxo-1,2-dihydroacenaphthylen-1-ylidene)hydrazinecarbothioamide(International Union of Crystallography, 2014-10-24) Vimala, G; Govindaraj, J; Haribabu, J; Karvembu, R; Subbiahpandi, AIn the title compound, C14H11N3OS, the acenaphthylene ring system and hydrazinecarbothioamide unit (=N - NH - C=S - NH-) are essentially coplanar [with maximum deviations from their mean planes of -0.009 (2) and 0.033 (2) Å, respectively], and make a dihedral angle of 1.59 (9)°. The molecular conformation is stabilized by two weak intramolecular hydrogen bonds (N - H⋯O and N - H⋯N), which generate S(6) and S(5) ring motifs. In the crystal, molecules are linked by N - H⋯S hydrogen bonds, forming chains along [010]. The chains are linked via pairs of C - H⋯O hydrogen bonds, enclosing R 2 2(10) ring motifs, and C - H⋯π interactions, forming a three-dimensional framework. The absolute structure of the title compound was determined by resonant scattering.Item Crystal structure of (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]hydrazinecarbothioamide(International Union of Crystallography, 2014-10-08) Vimala, G; Govindaraj, J; Haribabu. J; Karvembu, R; Subbiahpandi, AIn the title compound, C12H11N3O2S, the dihedral angle between the 4H-chromen-4-one ring system and the -CH=N - NH - CS - NH- unit is 6.22 (1)°. In the crystal, inversion dimers linked by pairs of N - H⋯O hydrogen bonds generate R 2/2(14) loops. The dimers are reinforced by a pair of C - H⋯O interactions, which generate R 2/2(10) loops.Item Crystal structure of (Z)-2-(1-benzyl-2- oxoindolin-3-ylidene)-N-phenylhydrazine-1-carbothioamide(International Union of Crystallography, 2015-02-07) Vimala, G; Haribabu, J; Karvembu, R; Phani Kumar, B.V.N; SubbiahPandi, AThe title compound, C22H18N4OS, crystallized with four independent molecules (A, B, C and D) in the asymmetric unit. All four molecules have a Z conformation about the C=N bond with the benzyl ring being inclined to the indoline ring mean planes by 73.4 (2), 77.9 (2), 73.2 (2) and 77.2 (2)° in molecules A, B, C and D, respectively. In molecules A and B, the phenyl ring is inclined to the mean plane of the indoline ring mean plane by 12.0 (2) and 12.2 (2)°, respectively. However, in molecules C and D, the same dihedral angles are larger, viz. 37.3 (2) and 36.4 (2)°, respectively. Consequently, the benzyl and phenyl rings are almost normal to one another in molecules A and B [dihedral angles = 80.3 (3) and 87.1 (3)°, respectively], while in molecules C and D, the same dihedral angles are only 48.8 (2) and 43.8 (3)°, respectively. There is an intramolecular N - H⋯O hydrogen bond in each molecule with an S(6) ring motif. There are also short intramolecular N - H⋯N and C - H⋯S contacts in each molecule. In the crystal, molecules are linked via C - H⋯S hydrogen bonds and C - H⋯π interactions, forming a three-dimensional structure. The crystal was refined as a non-merohedral twin with a final BASF value of 0.110 (1).Item Dibenzylazanium chloride(International Union of Crystallography, 2012-02-04) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.In the title salt, C 14H 16N +·Cl -, the complete cation and complete anion are generated by the application of mirror symmetry. The molecule is nonplanar, as seen in the dihedral angle between the terminal phenyl rings [70.92 (5)°]. In the crystal, N - H⋯Cl hydrogen bonds involving both azanium H atoms link the ions into a zigzag supramolecular chain along [100].Item Dicyclohexylammonium thiocyanate: Monoclinic polymorph(International Union of Crystallography, 2011-10-05) Selvakumaran, N; Karvembu, R; Ng, Seik Weng; Tiekink, Edward R. T.The title salt, C12H24N+·NCS -, represents a monoclinic polymorph of the previously reported ortho-rhom-bic form [Khawar Rauf et al. (2008). Acta Cryst. E64, o366]. Two independent formula units comprise the asymmetric unit with the major difference in their mol-ecular structures relating to the relative dispositions of the cyclohexyl rings [dihedral angles = 79.88 (6) and 67.72 (5)°]. Further, the independent anions form distinctive patterns of hydrogen-bonding interactions, i.e. 2 × N - H⋯N versus N - H⋯N and N - H⋯S. The resulting supra-molecular architecture is a supra-molecular chain along the c axis based on a square-wave topology. © Selvakumaran et al. 2011.