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Kanagathara N.,Vel Technology Multi Technology Dr Rangarajan Dr Sakunthala Enginering College | Chakkaravarthi G.,CPCL Polytechnic College | Marchewka M.K.,Institute of Low Temperature And Structure Research | Gunasekaran S.,Pachiayappas College | Anbalagan G.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the title adduct, 2C6H5NO3· C3H6N6·H2O, the melamine and the two independent nitrophenol molecules are essentially planar, with maximum deviations of 0.0294 (10), 0.0706 (12) and 0.0742 (12) Å, respectively. In the crystal, N - H⋯N, O - H⋯N, N - H⋯O and O - H⋯O hydrogen bonds link the components into a three-dimensional network. In addition, weak π-π interactions [centroid-centroid distances = 3.728 (3) and 3.749 (3) Å] are observed. © 2012 International Union of Crystallography.

Praveen Kumar P.,Presidency College at Chennai | Chakkaravarthi G.,CPCL Polytechnic College
Acta Crystallographica Section E: Crystallographic Communications | Year: 2015

The title molecular salt, C8H12N+·C7H5O3 - arose from the proton-transfer reaction between 2,5-xylidine and salicylic acid. In the anion, the dihedral angle between the planes of the aromatic ring and the -CO2 - group is 11.08 (8)°; this near planarity is consolidated by an intramolecular O-H⋯O hydrogen bond. In the crystal, the components are connected by N-H⋯O hydrogen bonds, with all three O atoms in the anion acting as acceptors; the result is a [100] chain. The structure also features weak C-H⋯O bonds and aromatic π-π stacking [centroid-to-centroid distance = 3.7416 (10) Å] interactions, which lead to a three-dimensional network.

Mathan Kumar S.,Government Arts College | Dhahagani K.,Government Arts College | Rajesh J.,Sethu Institute of Technology | Nehru K.,Anna University | And 3 more authors.
Polyhedron | Year: 2013

A new kind of Ni(II) complex of the type, [Ni(PPh3)(L)](1), {where L = chemosensor thiosemicarbazone = 2-(3-bromo-5-chloro-2- hydroxybenzylidene)-N-phenyhydrazine-carbothioamide} have been synthesized and characterized by NMR, IR, UV-Vis spectroscopic methods and single crystal X-ray studies. Based on spectroscopic and X-ray crystallographic studies, a square planar structure has been proposed for the Ni(II) complex. The interaction between Ni(II) complex and CT-DNA has been investigated using UV-Vis, circular dichroism studies and gel electrophoresis. In UV studies, the observed strong hypochromism in absorption intensities and binding constant value (Kb = 1.8 × 105) indicates significant interaction between the electronic states of the Ni(II) complex chromophore with that of DNA bases. With increasing concentration of Ni(II) complex, the peaks at 275 and 245 nm of CT-DNA are shifted to 1-2 nm without any change in the zero-cross over at 259 nm in circular dichroism studies. These observations suggest that the complex bind to DNA through a non-intercalative mode due to the waggling of three phenyl rings of triphenyl phosphine group. The Ni(II) complex display significant hydrolytic cleavage of circular plasmid pUC18 DNA. At high concentration, the Ni(II) complex almost promotes the maximum conversion of DNA from form I to form II along with the appearance of form III. The newly synthesized thiosemicarbazone compound is a promising system for the development of new colorimetric probes for the detection of anions. Anion sensing ability of the receptor (L) with halide ions (F-, Cl-, Br- and I-) have been carried out in different solvents. The receptor shows a remarkable color change from colorless to dark orange in CH3CN solution on selective binding with fluoride ion. The anion recognition property of the receptor via hydrogen bonding interactions is monitored by UV-Vis titration and 1H NMR spectroscopy. © 2013 Elsevier Ltd. All rights reserved.

Sudhahar S.,Presidency College at Chennai | Krishnakumar M.,Presidency College at Chennai | Sornamurthy B.M.,Presidency College at Chennai | Chakkaravarthi G.,CPCL Polytechnic College | Mohankumar R.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the crystal structure of the title salt, C6H8N +·C7H8O3 -, the anions and cations are linked by classical N - H⋯O hydrogen bonds. The anions are connected by pairs of C - H⋯O hydrogen bonds into inversion dimers and further linked by classical O - H⋯O hydrogen bonds. Weak π-π interactions [centroid-centroid distances = 3.740 (3) and 3.855 (3) Å] also occur. The dihedral angle between the CO2 - group and the benzene ring to which it is attached is 20.95 (8)°.

Umadevi M.,Bharathiyar University | Saravanan V.,University of Madras | Yamuna R.,Amrita University | Mohanakrishnan A.K.,University of Madras | Chakkaravarthi G.,CPCL Polytechnic College
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the title compound, C25H19ClN2O 5S, the phenyl ring forms dihedral angles of 79.62 (12) and 80.02 (13)° with the indole ring system and the benzene ring, respectively. The nitro group is twisted at an angle of 22.39 (11)° with respect to the attached benzene ring. In the crystal, molecules assemble into double layers in the ab plane via C-H⋯O interactions.

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