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Struktura pochodnych benzo[ b]furanu i kumaryny oraz ich kompleksów z miedzią (II) i cynkiem(II)

Drzewiecka A.

Wiadomości Chemiczne

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2012

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[Z] 66, 3-4

355-369

EN

Selected benzo[b]furan and coumarin derivatives with proven and potential antibacterial, anticancer and antiarrhythmic activities have been investigated [1–3] (Figs. 1 and 2). The stereochemical description of their molecules in the solid and gas phase as well as intra- and intermolecular-interactions in crystals have been determined [4–6]. The structural studies of analyzed molecules indicated the planarity of the benzo[b]furan and coumarin ring systems. The oxygen or carbon atoms of the substituents, –OH, –OCH3, –C(=O)CH3 and –COO H, are nearly coplanar with the aromatic ring. The hydroxyl and acetyl groups, being in the ortho position, are coplanar with the aromatic ring and the formation of the intramolecular O–H…O hydrogen bond in all three states of matter is observed. Its strength is around 18 kcal/mol. Several conformers of studied compounds, differing in the orientation of the methoxy, acetyl and/or carboxyl groups, were analyzed. Next, the electrochemical method was used to synthesize novel copper and zinc complexes with the oxygen donor benzo[b]furan and coumarin derivatives. The Cu(II) and Zn(II) complexes have been obtained with carboxylic acids as ligands whereas hydroxy ligands reacted only with copper [6]. The geometry of metal-ligand interaction of new compounds has been determined using a single crystal X-ray crystallography and an X-ray absorption spectroscopy [7, 8]. The combination of these two methods revealed that for some compounds cation environment could depend on the form of the solid sample. In the microcrystalline zinc complexes (studied by EXAFS) the cation is penta-coordinated (ZnO5) with the Zn–O distances being ca 1.98(3) Ĺ. In the recrystallized complex (analyzed by the X-ray diffraction) it was found that zinc is tetra-coordinated (ZnO4). The Cu(II) cation in the singlecrystal form of the complex with the carboxylic acid 5 is penta-coordinated to the carboxylate groups and the ethanol molecule. The bridging COO – groups stabilize the dinuclear complex center Cu2O10. The powdered form of this complex is based on the Cu2O8 units, indicating the absence of the ethanol molecule in the coordination sphere. In the series of the Cu(II) complexes with the hydroxy derivatives of benzo[b]furan and coumarin a centrosymmetric coordination polyhedron of metal exhibits a square-planar geometry (CuO4). Two ligands are bonded to the copper cation via the acetyl and deprotonated hydroxyl O atoms.

2

Structural and Spectroscopic Study of trans-Bis(1,3,5-trimethylpyrazole)-bis(O,O'-nitrate) Copper(II) Complex

Wiśniewski Z., Wojciechowska A., Kochel A., Wysokiński R.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 7

1277-1288

EN

Cu II complex with 1,3,5-trimethylpyrazole (1,3,5-TMePz) trans-[Cu(1,3,5-TMePz)2(NO3)2] has been prepared and studied by X-ray diffraction, vibrational and electronic spectroscopy. The complex crystallizes in the orthorhombic crystal system, P212121 space group with lattice parameters:a = 7.6784(8),b = 13.5856(11), c = 16.3372(13) capital A ring, V = 1704.2(3)capital A ring 3 and Z = 4. The hydrogen bond system stabilizes the crystal structure. Two nitrogen atoms of 1,3,5-TMePz and four oxygen atoms of chelating NO-3 groups form a trans-CuIIN2O2O2 ' chromophore.

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Magnetic, Electrochemical and Antimicrobial Properties of Some Cu(II) Complexes with TPMC

Vuckovic G., Antonijevic-Nikolic M., Korabik M., Mroziński J., Manojlovic D., Gojgic-Cvijovic G., Matsumoto N.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 4

679-687

EN

Three complexes: [Cu2(C6H5COO)tpmc](ClO4)3.CH3OH, (A), (tpmc = N,N',N'',N'''- tetrakis(2-pyridilmethyl)-1,4,8,11-tetraazacyclotetradecane), [Cu2(Hpht)tpmc](ClO4)3.3H2O (H2pht = phtalic acid) (B) and [Cu4(ipht)(tpmc)2](ClO4)6_NaClO4_2CH3CN (H2ipht = isophtalic acid) (C) previously described were investigated by magnetic measurements, cyclic voltammetry (CV) and were tested towards some strains of microorganisms. It is found that all three complexes were electrochemically stable in the investigated ranges. The least stable was mi-iphtcomplex (C) due to the reaction of central ion, which is seen from weak peaks in its cyclic voltammogram. Complexes were characterized by variable temperature magnetic measurements (4.2-300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H= - 2JSS1 2, giving the ferromagnetic exchange parameters J = 0.92 cm-1 forA, J = 0.55 cm-1 forB and J= 0.65 cm-1for C. For the complex C model of molecular magnet with two magnetically isolated dimeric subunits was used. These results indicate the presence of weak ferromagnetic spin exchange interaction between the CuII magnetic centers within each molecule.

4

Synthesis, X-ray Crystal Structure and Solution Studies of Cu(II) Complexes of a Pyridine Containing Self-Assembling System

Ranjbar M., Taghavipur M., Aghabozorg H., Moghimi A., Jalali F., Shamsipur M.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 6

785-794

EN

The complexation of a novel pyridine containing self-assembling system LH2, ([pyda_H2] [pydc] (pyda = 2,6-pyridinediamine and pydc_H2 = 2,6-pyridinedicarboxylic acid), with copper(II) acetate leads to the formation of an anionic self-assemble coordination compound, [(pyda_H)]2[Cu(pydc)2]_H2O. The crystal system is monoclinic with a space group P21/n and contains four molecules per unit cell. The unit cell dimensions are: a = 8.2567(19) A, b = 13.097(31) A, c = 23.384(6) A and _ = 94.685(5)_. The four carboxylate groups of two dianions are oriented in a flattened tetrahedral arrangement and the two dianionic units are almost perpendicular to each other. The axial N-Cu-N angle shows 2.65_ deviation from linearity. The complexation reactions in aqueous solution were investigated by potentiometric pH titrations and the equilibrium constants for all major complexes formed are described. The results are presented in the form of distribution diagrams revealing the concentration of individual complex species as a function of pH. The results revealed that, at pH = 4-5, the major complex species in solution is [(pyda_H)]2[Cu(pydc)2].