Search results for "perch"
showing 10 items of 1084 documents
CuCl catalyzed radical cyclisation of N-alpha-perchloroacyl-ketene-N,S-acetals: a new way to prepare disubstituted maleic anhydrides
2012
The discovery that cycloalkanes can form thermomorphic systems with typical polar organic solvents has led to the development of less-polar electrolyte solutions. Their mixing and separation can be regulated reversibly at a moderate temperature range. The phase switching temperature can be controlled by changing the solvent compositions. While biphasic conditions are maintained below the phase switching temperature, conductive monophasic conditions as less-polar electrolyte solutions are obtained above the phase switching temperature. After the electrochemical transformations, biphasic conditions are reconstructed below the phase switching temperature, facilitating the separation of cycloal…
Polynuclear copper(II) complexes with hexadentate Schiff base directed by the counter ion. Syntheses, crystal structures and magnetic properties
2018
Abstract Four new complexes, [Cu 9 L 6 ( µ 3 -ClO 4 ) 2 ](ClO 4 ) 4 ·4CHCl 3 1 , [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O 2 , [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 3 and [Cu 2 L(CH 3 COO) 2 ] 4 , where H 2 L stands for the Schiff base N , N ′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine, were obtained and structurally characterized. Compounds 1 , 2 and 3 contain the Cu 3 L 2 2+ entities in which L 2− acts in an unsymmetrical mode with N 3 O donor set wrapped around marginal copper(II) and with the remained NO sets bound to the central copper ion. The marginal copper(II) ions are in distorted square pyramidal environment, whereas that of the central one is square planar. In 1 , the peripheral …
New complexes of Ni(II) and Co(III) with a Schiff-base ligand derived from o -vanillin. Crystal structure, magnetic and catalytic properties of a dis…
2018
Abstract A binuclear complex, [Ni2L2(NO3)(H2O)(CH3CN)]ClO4·CH3CN (1), has been obtained using a Schiff-base ligand (HL) derived from o-vanillin and 4-(2-aminoethyl)morpholine. The crystal structure of 1 has been solved. Both Ni(II) ions are hexacoordinated, but they display different coordination spheres. The exchange interaction between the two nickel ions is antiferromagnetic (J = −7.9 ± 0.2 cm−1; H = −JS1S2), in line with the DFT calculations. Compound 1 has been tested as a catalyst in the epoxidation of various olefins. The reaction of the same ligand with a mixture of cobalt(II) perchlorate and nitrate affords a mononuclear Co(III) complex, [CoL2(H2O)]ClO4·CH3OH (2).
Anion modulated structural variations in copper(II) complexes with a semicarbazone Schiff base: Synthesis, characterization and self assembly
2014
Abstract Two copper(II) complexes, [Cu(L)N3]n (1) and [Cu(HL)2](I3)ClO4 (2), where HL = 2-pyridylaldehydesemicarbazone, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complex 1 crystallizes in monoclinic space group P21/a, whereas, complex 2 crystallizes in triclinic space group P-1. Complex 1 is a stair-like coordination polymer with square pyramidal geometry of copper(II), whereas, complex 2 is a mononuclear cationic bis-ligand complex of octahedral copper(II). Lower coordination ability of tri-iodide or perchlorate compared to azide may be related with variations of the structures of the complexes.
Synthesis and spectral studies on metal complexes with the neutral O,N,O-tridentate Schiff base 6-amino-5-formyl-1,3-dimethyluracil-benzoylhydrazone
1999
Abstract From the reaction between different Co(II), Cu(II), Zn(II) and Pd(II) salts and the Schiff base 6-amino-5-formyl-1,3-dimethyluracil-benzoylhydrazone (H 2 BEZDO), in ethanol and acetone media, five complexes with M/L stoichiometry 1/1, containing the neutral organic ligand, have been obtained. These compounds have been studied by IR, 13 C and 1 H-NMR, UV-VIS-NIR and EPR spectroscopies and magnetic measurements. A single crystal X-ray diffraction study has been carried out on the compound [Cu(ClO 4 )(H 2 BEZDO)(H 2 O)]ClO 4 . The structure consists of mononuclear cations [Cu(ClO 4 )(H 2 BEZDO)(H 2 O)] + and uncoordinated perchlorate anions. The coordination environment around the Cu(…
Structure of the copper (II) perchlorate complex with Schiff base ligand containing pyridine N-oxide fragments and propylene bridges: Solvatochromic …
2005
Abstract The copper (II) perchlorate complexes with Schiff base ligands were investigated by X-ray single crystal analysis, electron spectroscopy, infrared and electron paramagnetic spectroscopy. The Schiff bases were obtained as condensation products of 2-pyridinecarboxaldehyde N-oxide with dipropylenetriamine (L1) and triethylenetetramine (L3), respectively. The structure of the complex [CuL2](ClO4)2 was solved. In the structure, the ligand exists in the form of aliphatic polyamine containing two Schiff bases in contrary to the free form of this ligand with one pyrimidine ring and one Schiff base. Electronic spectra of the copper (II) perchlorate complexes of both ligands in different sol…
2-Amino-2-methyl-1,3-propanediol (ampdH2) as ligand backbone for the synthesis of cobalt complexes: Mononuclear Co(II), binuclear Co(II,III) and hexa…
2013
Abstract Three cobalt complexes have been synthesized using 2-amino-2-methyl-1,3-propanediol (ampdH2) and its Schiff base derivative ligands and structurally characterized. The three complexes 1, 2 and 3 are very different and consist of mononuclear Co(II), mixed-valence binuclear Co(II,III) and mixed-valence hexanuclear Co(II,III) complexes respectively. The properties of the coordinated donor atoms of the ligand play the predominant role in stabilizing the oxidation states of the cobalt centers. The presence of intermolecular hydrogen bonds in 1 via non-coordinating perchlorate ions lead to the formation of a 1D-Chain network while a sheet-like 2D network was observed in 3.
Documento di consenso intersocietario ANMCO/ISS/AMD/ANCE/ARCA/FADOI/ GICR-IACPR/SICI-GISE/SIBioC/SIC/SICOA/ SID/SIF/SIMEU/SIMG/SIMI/SISA Colesterolo …
2016
Atherosclerotic cardiovascular disease still represents the leading cause of death in western countries. A wealth of scientific evidence demonstrates that increased blood cholesterol levels have a major impact on the outbreak and progression of atherosclerotic plaques. Moreover, several cholesterol-lowering pharmacological agents, including statins and ezetimibe, have proven effective in improving clinical outcomes. This document is focused on the clinical management of hypercholesterolemia and has been conceived by 16 Italian medical associations with the support of the Italian National Institute of Health. The authors have considered with particular attention the role of hypercholesterole…
Formation Of perched leachate zones in MSW landfill
2010
The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model is based on mass balance equations, that enable one to simulate the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the in and out flow throughout each layer as well as the continuous moisture distribution. The infiltration flow is evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solu…
Lipid and apoprotein composition of HDL in partial or complete CETP deficiency
2012
Hyperalphalipoproteinemia, as observed in patients who are either homozygous or heterozygous for cholesteryl ester transfer protein (CETP) deficiency, has been shown to be associated with striking changes in apolipoprotein size distribution, namely, of high-density lipoprotein (HDL) and HDL-like particles. We compared the effect of varying degrees of CETP activity on the HDL apolipoprotein profile in Caucasian CETP-deficient subjects and following pharmacological decrease in CETP activity, using Size Exclusion Chromatography followed by Reverse Phase Protein Array (SEC RPA). The main HDL-associated apolipoproteins (Apo), i.e. ApoA-I, ApoA-II, ApoC-I, and ApoC-III, co-eluted with the HDL pea…