Search results for "Magnetic Susceptibility"
showing 10 items of 516 documents
Exchange interactions through hydrogen-bond bridges. Crystal structure, spectroscopic characterisation and magnetic properties of the complex [{Cu(en…
1998
Abstract The structure and spectroscopic and magnetic properties of [{Cu(en)}2(μ-egta)]·4H2O (H4egta = 3,12-bis(carboxymethyl)-6–9-dio 3,12-diazatetradecanedioic acid) are described. The compound is built of centrosymmetric neutral dimeric {[Cu(en)}2(μ-egta)] entities linked through hydrogen bonds involving water molecules. -NH2 groups and -CO2 groups, affording a three-dimensional framework. The egta anion displays an opened-up structure acting as a bridging ligand between two copper atoms. The coordination geometry about the metal atoms can be viewed as 4 + 1 + 1 (CuN3OO′O″ chromophores). The EPR spectra are indicative of an essentially dv−v ground state for the copper(II) ions. Magnetic …
Synthesis and characterization of four novel manganese(II) chains formed by 4,4′-azobis(pyridine) and benzoate or nitrobenzoates: Stabilization of un…
2013
Abstract Four new manganese(II) coordination polymers: [Mn(4,4′-azpy)(C6H5COO)2](4,4′-azpy)0.5 (1), [Mn(4,4′-azpy)(p-(NO2)C6H4COO)2] (2), [Mn(4,4′-azpy)(m-(NO2)C6H4COO)2] (3) and [Mn(4,4′-azpy)(o-(NO2)C6H4COO)2(H2O)2] (4), where 4,4′-azpy = 4,4′-azobis(pyridine), have been synthesized by self-assembly of MnX2 (X = benzoate, p-, m-, or o-nitrobenzoates) together with 4,4′-azpy. All four complexes were characterized by elemental analyses, IR spectroscopy, thermal analyses, single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that complexes 1, 2 and 3 feature a 1D molecular ladder formed by syn–syn (complex 1) or syn–anti (com…
Chromium(III) complexes with 2-(2′-pyridyl)imidazole: Synthesis, crystal structure and magnetic properties
2011
Abstract The preparation, crystal structure and variable temperature-magnetic investigation of three 2-(2′-pyridyl)imidazole-containing chromium(III) complexes of formula PPh4[Cr(pyim)(C2O4)2]·H2O (1), AsPh4[Cr(pyim)(C2O4)2]·H2O (2) and [Cr2(pyim)2(C2O4)2(OH2)2]·2pyim · 6H2O (3) [pyim = 2-(2′-pyridyl)imidazole, C 2 O 4 2 - = dianion of oxalic acid , PPh 4 + = tetraphenylphosphonium cation and AsPh 4 + = tetraphenylarsonium cation ] are reported herein. The isomorphous compounds are made up of discrete [Cr(pyim)(C2O4)2]− anions, XPh 4 + cations [X = P (1) and As (2)] and uncoordinated water molecules. The chromium environment in 1 and 2 is distorted octahedral with Cr–N and Cr–O bond distanc…
Synthesis, structure and magnetic properties of Mn(II) and Cu(II) complexes with the dicyano-acetic acid methyl ester anion
2001
The preparation of the sodium salt of dicyano-acetic acid methyl ester (NaCH 3 OC(O)C(CN) 2 ) (NaL) is reported. The structure of this anion is related to the structure of the dicyanamide, whose chelating capability has been used to develop 2D networks. Two new complexes of formula [M(L) 2 (H 2 O) 2 ] (M=Mn 2+ ( 1 ) and Cu 2+ ( 2 )) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. The coordination geometry of Mn atom in 1 is approximately octahedral, and the Mn atoms are μ 2 -bridged by two pairs of L − resulting in an infinite one-dimensional chain. Two types of hydrogen bonds link the chains within a 3-dimensional infinite lattice. The coo…
Hepta- and tetra-nuclear copper(II) clusters self-assembled by cyano- and azacyano-carbanions
2015
International audience; Two polynuclear copper(II) complexes with hydroxido-bridging ligands and polycyanide units, [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2](tcm)4Cl2·2H2O (1) and [{Cu(bpy)}4(OH)4(dca)2](dca)2·bpy·2H2O (2) (tn = NH2(CH2)3NH2; tcm− = [C(CN)3]−, bpy = 2,2′-bipyridyl, dca− = [N(CN)2]−) have been prepared by one-pot reactions. The structure of 1 consists of a centrosymmetric heptanuclear ion [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2]6+. The tcm− and the halide anions which appear as counter-ions in the formula unit, play an important role in the stabilization of the complex since the hydrogen bonding between nitrogen atoms of the tcm− anion and halide anions, and hydrogen atoms of the terminal wa…
Protonated malonate: the influence of the hydrogen bonds on the magnetic behaviour
2004
One hydrogen malonato-bridged complex of formula [Cu(Hmal)2] (1) and two polymorphous malonato-bridged complexes of formula [Cu(H2O)(H2mal)(mal)] (2 and 3), in which the three species of the malonate (H2mal, Hmal−, and mal2−) are present, were synthesised and characterized by X-ray diffraction [H2mal = malonic acid]. Their structures consist of corrugated malonate layers of [Cu(Hmal)2] (1) and [Cu(H2O)(H2mal)(mal)] (2 and 3) units bridged by carboxylate–malonate groups. The layers are linked through hydrogen bonds leading to a three-dimensional network. Variable-temperature (1.9–290 K) magnetic susceptibility measurements indicate the occurrence of weak ferromagnetic interactions between th…
Application of Magnetic Susceptibility Measurements for Identification of Technogenic Horizons in Soil Profiles on the Example of the Vistula River C…
2017
Studies on magnetic properties of soils have been recently applied in the soil environment quality monitoring in relation to basic physical and chemical properties. However, the issue of distribution of ferrimagnetic materials in particular genetic soil horizons, especially in altered soils, has not yet been considered in environmental studies. The main subject of the research was to evaluate a potential of magnetic susceptibility measurements as implements for supporting the soil classification through indication of particular distinctive genetic horizons in the soil profile. The study objects were soils whose formation was strictly conditioned by hydrotechnical regulations in the area of …
Sediment origin and pedogenesis in the former mill pond basin of Turznice (north-central Poland) based on magnetic susceptibility measurements
2016
Abstract This paper aims to assess the usefulness of magnetic susceptibility measurements in pedological studies of mill pond sediments. The study area includes the former Turznice mill pond basin located in the south-eastern part of the Grudziądz Basin. Four soil profiles were selected within the transect located along the longitudinal axis of the basin. The following soil properties were determined in the collected samples: bulk density, particle size distribution, pH, content of carbonates, approximate content of organic matter (LOI), total organic carbon (TOC), total nitrogen (Nt), and the pseudo-total contents of metals (Fe, Mn, Cu, Zn, Pb, Ni, Cd). The obtained results were correlated…
Mapping Sediment Accumulation Rate by using Volume magnetic Susceptibility Core Correlation in a contaminated Bay (Lake Geneva, Switzerland)
2003
The Bay of Vidy is the most contaminated area of Lake Geneva: contamination is caused by the effluent of the sewage treatment plant (STP) of the City of Lausanne. The implementation of a chemical stage in the treatment plant to remove phosphorus using FeC13 in 1971 is indirectly recorded in the lake sediments by a strong and sharp increase in the volume magnetic susceptibility (VMS) signal. A total of 43 sediment cores have been retrieved and measured for VMS. The synchronism of the VMS signal increase and its relation to the implementation of the P-removal stage in the STP has been shown in seven 137Cs-dated sediment cores. The VMS signal has been used to date by stratigraphie correlation …
Metal Phosphonates Based on {[(Benzimidazol‐2‐ylmethyl)imino]bis(methylene)}bis(phosphonic Acid): Syntheses, Structures and Magnetic Properties of th…
2006
Five compounds based on {[(benzimidazol-2-ylmethyl)imino]bis(methylene)}bis(phosphonic acid) [(C7H5N2)CH2N(CH2PO3H2)2], namely [M{(C7H5N2)CH2N(CH2PO3H)2}] [M = Mn (1), Fe (2), Co (3), Cu (4), Cd (5)] have been synthesized under hydrothermal conditions. These compounds are isostructural, crystallizing in the orthorhombic space group Pbca, with a = 15.331(2), b = 10.7150(16), and c = 16.715(2) A for 1; a = 15.320(3), b = 10.477(2), and c = 16.764(3) A for 2; a = 15.207(2), b = 10.4626(16), and c = 16.794(3) A for 3; a = 15.101(3), b = 10.3517(17), and c = 16.997(3) A for 4; and a = 15.4679(19), b = 10.8923(13), and c = 16.6175(19) for 5. Each compound shows a one-dimensional chain structure w…