Vibrational spectroscopic studies and computational study of quinoline-2-carbaldehyde benzoyl hydrazone

FT-IR spectrum of quinoline-2-carbaldehyde benzoyl hydrazone (HQb H2O) was recorded and analyzed. The synthesis and crystal structure data are also described. The vibrational wavenumbers were examined theoretically using the Gaussian03 package of programs using HF/6-31G(d) and B3LYP/6-31G(d) levels of theory. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands obtained in infrared spectroscopy of the studied molecule. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non-linear optics. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated values. The changes in the CAN bond lengths suggest an extended p-electron delocalization over quinoline and hydrazone moieties which is responsible for the non-linearity of the molecule

2-Chlorobenzo[h]quinoline-3-carbaldehyde

The benzo[h] quinolinyl fused-ring of the title compound, C14H8ClNO, is planar (r.m.s. deviation = 0.016 angstrom); the formyl group is slightly bent out of the plane [the C-C-C-O torsion angle is 10.7 (4)degrees].

Evaluation of DNA binding, antioxidant and cytotoxic activity of mononuclear Co(III) complexes of 2-oxo-1,2-dihydrobenzoh]quinoline-3-carbaldehyde thiosemicarbazones

Four new 2-oxo-1,2-dihydrobenzoh]quinoline-3-carbaldehyde N-substituted thiosemicarbazone ligands (H-2-LR, where R = H, Me, Et or Ph) and their corresponding new cobalt(III) complexes have been synthesized and characterized. The structures of the complexes 2 and 3 were determined by single crystal X-ray diffraction analysis. The interactions of the new complexes with DNA were investigated by absorption, emission and viscosity studies which indicated that the complexes bind to DNA via intercalation. Antioxidant studies of the new complexes showed that the significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of complexes 1-4 against A549 cell line was assayed which showed higher cytotoxic activity with lower IC50 values indicating their efficiency in killing the cancer cells even at very low concentrations. (C) 2012 Elsevier Masson SAS. All rights reserved.

Guanidinium quinoline-2-carboxylate

In the structure of the guanidinium salt of quinaldic acid, CH6N3+ C10H6NO2-, the asymmetric unit contains two independent cations and anions having similar inter-species hydrogen-bonding environments which include cyclic R2/2(8), R1/2(6) and R2/1(5) associations. These and additional weak aromatic ring pi-pi interactions [minimum ring centroid separation, 3.6621(16)A] give a two-dimensional layered structure.

(E)-6-fluoropyridine-2-carbaldehyde oxime

The title compound, C6H5FN2O, exists as the E isomer. The crystal structure is stabilized by O-(HN)-N-... hydrogen bonding.

(E)-quinoline-4-carbaldehyde oxime

The title compound, C10H8N2O, exists as the E isomer. The crystal packing is stabilized by intermolecular O - (HN)-N-... and C - (HN)-N-... hydrogen bonds, as well as pi-pi stacking.

Two novel bis-azomethines derived from quinoxaline-2-carbaldehyde

The Schiff base compounds N,N0-bis[(E)-quinoxalin-2-ylmethylidene] propane-1,3-diamine, C21H18N6, (I), and N,N0-bis[(E)- quinoxalin-2-ylmethylidene]butane-1,4-diamine, C22H20N6, (II), crystallize in the monoclinic crystal system. These molecules have crystallographically imposed symmetry. Compound (I) is located on a crystallographic twofold axis and (II) is located on an inversion centre. The molecular conformations of these crystal structures are stabilized by aromatic pye stacking interactions.

Copper(II) complexes of N(4)-substituted thiosemicarbazones derived from pyridine-2-carbaldehyde: Crystal structure of a binuclear complex

Ten copper(II) complexes {[CuL1Cl] (1), [CuL1NO3]2 (2), [CuL1N3]2 · 2/3H2O (3), [CuL1]2(ClO4)2 · 2H2O (4), [CuL2Cl]2 (5), [CuL2N3] (6), [Cu(HL2)SO4]2 · 4H2O (7), [Cu(HL2)2] (ClO4)2 · 1/2EtOH (8), [CuL3Cl]2 (9), [CuL3NCS] · 1/2H2O (10)} of three NNS donor thiosemicarbazone ligands {pyridine-2-carbaldehyde-N(4)-p-methoxyphenyl thiosemicarbazone [HL1], pyridine-2-carbaldehyde-N(4)-2-phenethyl thiosemicarbazone [HL2] and pyridine-2-carbaldehyde N(4)-(methyl), N(4)-(phenyl) thiosemicarbazone [HL3]} were synthesized and physico-chemically characterized. The crystal structure of compound 9 has been determined by X-ray diffraction studies and is found that the dimer consists of two square pyramidal Cu(II) centers linked by two chlorine atoms.

Structural and spectral studies of novel Co(III) complexes of N(4)-substituted thiosemicarbazones derived from pyridine-2-carbaldehyde

Seven bis(ligand) Co(III) complexes {[CoL21] NO3 · H2 O (1), [CoL21] Cl · 2 H2 O (2),[CoL21] ClO4 (3), [CoL22] NO3 (4), [CoL22] Cl · 2 H2 O (5), [CoL23] Br · 2 H2 O (6), [CoL23] ClO4 · H2 O (7)} of three thiosemicarbazone ligands {pyridine-2-carbaldehyde-N(4)-p-methoxyphenyl thiosemicarbazone [HL1], pyridine-2-carbaldehyde-N(4)-2-phenylethyl thiosemicarbazone [HL2] and pyridine-2-carbaldehyde-N(4)-(methyl),N(4)-(phenyl) thiosemicarbazone [HL3]} were synthesized and physico-chemically characterized. All complexes are assigned octahedral geometries on the basis of spectral studies. The ligands deprotonate and coordinate by means of pyridine nitrogen, azomethine nitrogen, and thiolate sulfur atoms. The single crystal X-ray structures of HL3 and two nitrate compounds are discussed. The structural studies corroborate the spectral characterization.

Synthesis, Spectral and Structural Studies of a Novel Semicarbazone Synthesized from Quinoline-2-Carboxaldehyde and N4-Phenyl-3-Semicarbazide

A new semicarbazone, HL has been synthesized from quinoline-2-carboxaldehyde and N4-phenyl-3- semicarbazide and structurally and spectrochemically characterized. 1H NMR, 13C NMR, IR and electronic spectra of the compound are studied. The existence of keto form in the solid state is supported by the crystal structure and IR data. The compound crystallizes into an orthorhombic space group P212121. Intra and intermolecular hydrogen bonding interactions facilitates unit cell packing in the crystal lattice

Structural and spectroscopic properties of Ru(II) complexes of 4-(aryl)thiosemicarbazones of thiophen-2-carbaldehyde

Six Ru(II) complexes of formula [Ru(L)(2)(PPh3)(2)] have been prepared where LH = 4-(aryl)thiosemicarbazones of thiophen-2-carbaldehyde. X-ray crystal structures of five of the complexes are reported. In all the complexes ruthenium is six coordinate with a distorted octahedral cis-P-2, cis-N-2, trans-S-2 donor environment, and each of the two thiosemicarbazone ligands are coordinated in a bidentate fashion forming a four membered chelate ring. The complexes undergo a one-electron oxidation at similar to 0.5 V vs. Ag/AgCl. The EPR spectrum of the electrochemically oxidized solution at 100 K shows a rhombic signal, with transitions at g(1) = 2.27, g(2) = 2.00 and g(3) = 1.80. DFT calculations on one of the complexes suggest that there is 35% ruthenium and 17% sulfur orbital contribution to the HOMO. These results suggest that the assignment of metal atom oxidation states in these compounds is not unambiguous. (C) 2009 Elsevier Ltd. All rights reserved.

SYNTHESIS AND CRYSTAL-STRUCTURE OF THE NOVEL CYCLOPALLADATED COMPLEX DI(MU,N-S-ETA(2)-QUINOLINE-2-THIOLATE)-BIS[(N,N-DIMETHYLBENZYLAMINE-C(2),N) PALLADIUM(II)]

The compound di(mu,N-Seta2-2-quinoline-2-thiolate)-bis[(N,N-dimethylbenzylamine-C2,N)palladium(II)] was synthesized and studied by IR, NMR and X-ray diffraction: monoclinic, a = 20.138(3), b = 10.831(1), c = 14.973(2) angstrom, beta = 98.04(1)-degrees, Z = 4, space group P2(1)/c, R = 0.032. The compound is dimeric with the two [Pd(N,N-dimethylbenzylamine)]moieties being connected by the two vicinal bridging eta2-N,S-quinoline-2-thiolate anions in a square-planar coordination geometry for the palladium atoms.

Reaction of pentacarbonyliron with a nitrogen heterocycle. X-ray crystal structure of bis[(carbonyl)(quinoline-2-thiolate-N,S)]iron(II)

The monomeric compound bis[(carbonyl)(quinoline-2-thiolate-N,S)]iron(II) was synthesized and studied by IR and Mossbauer spectroscopy, cyclic voltammetry and X-ray diffraction. The molecule has two terminal carbonyl groups and two quinoline-2-thiolate anions coordinated as N,S-donor chelates, and the iron atom shows an octahedral coordination geometry.

Synthesis, X-ray structure and in vitro cytotoxicity studies of Cu(I/II) complexes of thiosemicarbazone: special emphasis on their interactions with DNA

4-(p-X-phenyl)thiosemicarbazone of napthaldehyde {where X = Cl (HL1) and X = Br (HL2)}, thiosemicarbazone of quinoline-2-carbaldehyde (HL3) and 4-(p-fluorophenyl) thiosemicarbazone of salicylaldehyde (H2L4) and their copper(I) {Cu(HL1)(PPh3)(2)Br]center dot CH3CN (1) and Cu(HL2)(PPh3)(2)Cl]center dot DMSO (2)} and copper(II) {((Cu2L2Cl)-Cl-3)(2)(mu-Cl)(2)]center dot 2H(2)O (3) and Cu(L-4)(Py)] (4)} complexes are reported herein. The synthesized ligands and their copper complexes were successfully characterized by elemental analysis, cyclic voltammetry, NMR, ESI-MS, IR and UV-Vis spectroscopy. Molecular structures of all the Cu(I) and Cu(II) complexes have been determined by X-ray crystallography. All the complexes (1-4) were tested for their ability to exhibit DNA-binding and - cleavage activity. The complexes effectively interact with CT-DNA possibly by groove binding mode, with binding constants ranging from 10(4) to 10(5) M-1. Among the complexes, 3 shows the highest chemical (60%) as well as photo-induced (80%) DNA cleavage activity against pUC19 DNA. Finally, the in vitro antiproliferative activity of all the complexes was assayed against the HeLa cell line. Some of the complexes have proved to be as active as the clinical referred drugs, and the greater potency of 3 may be correlated with its aqueous solubility and the presence of the quinonoidal group in the thiosemicarbazone ligand coordinated to the metal.