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Isomeric forms of Cu(quinoline -2-carboxylate)2.H2O compound: Spectroscopic, and magnetic properties

Żurowska B., Mroziński J.

Materials Science Poland

2005

Vol. 23, No. 3

737--744

Spectroscopic and magnetic data of the compound Cu(2-qic)2 .H2O (1), where 2-qic is quinoline-2-carboxylate in the light of the known X-ray structure were studied. The geometry of CuN2O3 chromophore shows a very distorted five-coordinate stereochemistry intermediate between tetragonal pyramid and trigonal bipyramid resulting from the didentate N,O-bonded two chelate ligands and one water molecule. The crystal structure is stabilized by extended hydrogen-bonding network. Magnetic data reflect the molecular character of the compound with very weak exchange interaction (zJ' = - 0.23 cm-1), transmitted through H-bonds. The physico-chemical properties of 1 are compared with a recently reported forms 2 and 3 of identical stoichiometries Cu(quinoline-2-carboxylate)2.H2O obtained in an unusual oxidative P-dealkylation reaction. The compound 1 was prepared directly from quinaldinic acid.

Preparation, Separation and Identification of Some para-Substituted ONN and NNO trans-Azoxybenzenes

Domański A. A., Kyzioł J. B.

Polish Journal of Chemistry

2001

Vol. 75, nr 12

1839-1846

A series of para-substituted azoxybenzenes was obtained as model compounds for the investigation on the mechanism of Wallach rearrangement. Oxidation of azobenzenes with hydrogen peroxide in acetic acid solution, provided mixtures of alfa and beta isomers. Some couples of the products were separated, using chromatography and crystallization techniques, and identifiedon the basis of their carbon NMR and mass spectra. The SCSDal-gorithm can be applied to the interpretation of the I3C-NMR spectra. Recognition of the ipso andpara carbons suffice to the identification of an isomer, hence there are no strong interactions between the azoxy group and another substituent across the aromatic ring. Fragmentation of azoxybenzenes under electron impact occurs preferentially on the oxidized side of the azoxy bridge. Relative intensities of daughter ions differentiate the ONN = a. and NNO = P isomers in most cases.