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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.


Sivakumar P.K.,MNM Jain Engineering College | Krishnakumar M.,Presidency College at Chennai | Kanagadurai R.,Presidency College at Chennai | Chakkaravarthi G.,CPCL Polytechnic College | Mohankumar R.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the cation of the title salt, C6H7N 2O2 +C7H7O 3S-, the benzene ring makes a dihedral angle of 10.2 (2)° with the nitro group. In the crystal, the cations and anions are linked by weak N - H···O hydrogen bonds, forming a layer parallel to the ac plane. A weak C - H···O interaction and π-π interactions [centroid-centroid distances of 3.738 (3) and 3.748 (3) Å] also observed within the layer.


Rajesh J.,Sethu Institute of Technology | Nehru K.,Anna University | Annaraj J.,Madurai Kamaraj University | Chakkaravarthi G.,CPCL Polytechnic College
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.


Sangeetha V.,Dg Vaishnav College | Kanagathara N.,Vel Technology Multi Technology Dr Rangarajan And Dr Sakunthala Engineering College | Chakkaravarthi G.,CPCL Polytechnic College | Marchewka M.K.,Institute of Low Temperature And Structure Research | Anbalagan G.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The asymmetric unit of the title salt, C3H7N 6 +·C6H7O4 -·C3H4O2·H 2O, contains a 2,4,6-triamino-1,3,5-triazin-1-ium cation, a 3-(prop-2-enoyloxy)propanoate anion and acrylic acid and water solvent molecules in a 1:1:1:1 ratio and with each species in a general position. In the crystal, the components are linked into a supramolecular layer in the bc plane via a combination of O - H⋯O, N - H⋯N and N - H⋯O hydrogen bonding. The crystal studied was a non-merohedral twin, the minor component contribution being approximately 26%.


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.


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)°.


Arularasan P.,Presidency College at Chennai | Sivakumar B.,Presidency College at Chennai | Chakkaravarthi G.,CPCL Polytechnic College | Mohan R.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The title compound, [Cu4Cl8(C6H 14N4O2)4], contains four molecules in the asymmetric unit. In the molecular structure, each of the four Cu 2+ ions binds to three Cl atoms, one N atom and one O atom, resulting in distorted square-pyramidal coordination environments. The molecular structure is stabilized by weak C - H⋯O and N - H⋯Cl hydrogen bonds. The crystal structure exhibit weak intermolecular N - H⋯O, C - H⋯O and N - H⋯Cl interactions, generating a three-dimensional network.


Jayamani A.,Alagappa University | Sengottuvelan N.,Alagappa University | Chakkaravarthi G.,CPCL Polytechnic College
Polyhedron | Year: 2014

The dimeric copper(II) complexes [Cu2(bpy)2(L 1)2(ClO4)2] (1), [Cu 2(biim)2(L1)2(ClO4) 2] (2), [Cu2(bpy)2(L2) 2](ClO4)2 (3) and [Cu2(biim) 2(L2)2](ClO4)2 (4) (where bpy = 2,2′-bipyridine, biim = 2,2′-biimidazole, L1 = 5-methylsalicylaldehyde and L2 = 5-bromosalicylic acid) have been synthesized and characterized by IR, UV-Vis, ESR and ESI-mass spectroscopy. The single crystal X-ray diffraction study of complexes 1 and 3 showed that the complexes crystallize in triclinic crystal system with the P1̄ space group. All the complexes showed one quasi-reversible redox wave in the cathodic region (E1 pc = -0.83 to -0.90 V), assignable to the Cu(II)/Cu(I) redox couple. The binding interaction of the complexes with calf thymus DNA (ctDNA) was investigated by absorption, fluorescence, circular dichroism spectral studies and molecular docking techniques. The copper(II) complexes showed good binding affinity to ctDNA and the intrinsic binding constants obtained from UV-Vis spectroscopic studies are 1.16 × 105, 3.19 × 105, 1.82 × 105 and 3.66 × 10 5 M-1 for complexes 1-4, respectively. The apparent binding constant obtained from fluorescence spectroscopic studies are 1.37 × 105, 3.33 × 105, 2.2 × 105 and 4.7 × 105 M-1 for the complexes 1-4, respectively. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid (MPA) and the cleavage process was found to proceed by a hydroxyl radical mechanism. The ligands and their Cu(II) complexes were screened for antimicrobial activities and the results indicated that the complexes exhibit significant antimicrobial activity compared to the free ligands. © 2014 Published by Elsevier Ltd.


Krishnakumar M.,Presidency College at Chennai | Sudhahar S.,Presidency College at Chennai | Silambarasan A.,Presidency College at Chennai | Chakkaravarthi G.,CPCL Polytechnic College | Mohankumar R.,Presidency College at Chennai
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the title salt, C15H16N+·C7H7O3S-, the dihedral angle between the pyridine and benzene rings of the cation is 5.98 (18)°. In the crystal, adjacent anions and cations are linked by weak non-classical C-H⋯O hydrogen bonds and π-π interactions, with a centroid-centroid distance of 3.749 (2) Å.


Chakkaravarthi G.,CPCL Polytechnic College | Anitha K.,Madurai Kamaraj University | Rajesh J.,Sethu Institute of Technology | Ramu A.,Madurai Kamaraj University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by 1H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M = Cu(II), Co(II)), Zn(II), or VO(IV); MPMP = 2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X = Cl, (L1H), X = Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines. © 2013 Elsevier B.V. All rights reserved.

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