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Magnetic Exchange Interactions (magnetic + exchange_interaction)
Selected AbstractsPorous Capsules {(M)M5}12FeIII30 (M=MoVI, WVI): Sphere Surface Supramolecular Chemistry with 20 Ammonium Ions, Related Solution Properties, and Tuning of Magnetic Exchange Interactions,ANGEWANDTE CHEMIE, Issue 3 2010Maria Todea Dr. Eine Vielfalt von Wasserstoffbrücken-Bindungsoptionen auf einer hochfunktionalisierten Kapseloberfläche mit 20 kronenetherartigen Poren ermöglicht die Fixierung/Erkennung von 20 Ammoniumionen (siehe Bild; W grün, Fe orange, O rot, N blau, H hellgrau), die in Lösung zum Teil abgegeben werden, und zwar unter Bildung entsprechender Gleichgewichte. [source] ChemInform Abstract: Porous Capsules {(M)M5}12FeIII30 (M: MoVI, WVI): Sphere Surface Supramolecular Chemistry with 20 Ammonium Ions, Related Solution Properties, and Tuning of Magnetic Exchange Interactions.CHEMINFORM, Issue 15 2010Achim Mueller Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Magnetic and Electrochemical Properties of a Heterobridged ,-Phenoxido,,1,1 -Azide Dinickel(II) Compound: A Unique Example Demonstrating the Bridge Distance Dependency of Exchange IntegralEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 33 2009Rajesh Koner Abstract The synthesis, structure, magnetic and electrochemical properties of the heterobridged ,-phenoxido,,1,1 -azide dinickel(II) compound [NiII2(HL1)3(,1,1 -N3)]·3H2O (1) derived from the tetradentate Schiff base ligand N -(2-hydroxyethyl)-3-methoxysalicylaldimine (H2L1) are described. The title compound crystallizes in the triclinic system (space group P). Electrochemical analyses reveal that compound 1 exhibits two-step quasireversible couples in the reduction window with E1/2 values of ,1412 and ,1762 mV. The variable-temperature (2,300 K) magnetic susceptibilities at 1 T of the title compound were measured. The interaction between the metal centres is weak ferromagnetic (J = 5.0 cm,1, g = 2.23, D1 = 29.2 cm,1 and D2 = 10.7 cm,1). Comparison of the exchange integral of 1 with that of the only reported ,-phenoxido,,1,1 -azide dinickel(II) compound results in the emergence of a unique example of the dependence of strength of magnetic exchange interaction on the metal,ligand bridge distance. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis and magnetic properties of poly(p-phthaloyl-disacetylaceton-ethylenediimine) metal complexes,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2002Yun-Pu Wang Abstract Macrocyclic Schiff-base ligand, bisacetylaceton-ethylenediimine (BAE) and its transition metal complexes M(BAE) (M,=,Cu2+, Ni2+) were synthesized. The complexes having characteristics of aromatic systems and well-defined one-dimensional structures, reacted with p-phthaloyl chloride, to obtain polymer complexes. The complexes were characterized by elemental analysis, inductively coupled plasma (ICP), FT-IR, and thermal analysis and show good thermal stability. ESR spectra analysis discovered that there are free radicals in the chain of polymers, indicating that a weak magnetic spin-exchange interaction operates between the metal ions and free radicals. It is found that, as the bridging p -phthaloyl group is able to propagate the magnetic exchange interaction, the polymer complexes show paramagnetic properties by measurement of temperature dependence of the magnetic property, and obey Curie,Weiss law. Copyright © 2001 John Wiley & Sons, Ltd. [source] Cyano-bridged Ln3+ -Cr3+ Binuclear Complexes [Ln(L)x(H2O)yCr(CN)6]·mL·nH2O (Ln=La,Nd, x=5, y=2, m=1 or 2, n=2 or 2.5; Ln=Sm,Dy, Er, x=4, y=3, m=0, n=1.5 or 2.0; L=2-pyrrolidinone): Structure, Magnetism and Spin Density MapCHINESE JOURNAL OF CHEMISTRY, Issue 3 2007Xian-Ru Sun Abstract In order to shed light upon the nature and mechanism of 4f-3d magnetic exchange interactions, a series of binuclear complexes of lanthanide(3+) and chromium(3+) with the general formula [Ln(L)5(H2O)2Cr(CN)6]·mL·nH2O (Ln=La (1), Ce (2), Pr (3), Nd (4); x=5, y=2, m=1 or 2, n=2 or 2.5; L=2-pyrrolidinone) and [Ln(L)4(H2O)3Cr(CN)6] ·nH2O (Ln=Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Er (10); x=4, y=3, m=0, n=1.5 or 2.0; L2-pyrrolidinone) were prepared and the X-ray crystal structures of complexes 2, 6 and 7 were determined. All the compounds consist of a Ln-CN-Cr unit, in which Ln3+ in a square antiprism environment is bridged to an octahedral coordinated Cr3+ ion through a cyano group. The magnetic properties of the complexes 3 and 6,10 show an overall antiferromagnetic behavior. The fitting to the experimental magnetic susceptibilities of 7 give g=1.98, J=0.40 cm,1, zJ,=,0.21 cm,1 on the basis of a binuclear spin system (SGd=7/2, SCr=3/2), revealing an intra-molecular Gd3+ -Cr3+ ferromagnetic interaction and an inter-molecular antiferromagnetic interaction. For 7 the calculation of quantum chemical density functional theory (DFT), combined with the broken symmetry approach, showed that the calculated spin coupling constant was 20.3 cm,1, supporting the observation of weak ferromagnetic intra-molecular interaction in 7. The spin density distributions of 7 in both the high spin ground state and the broken symmetry state were obtained, and the spin coupling mechanism between Gd3+ and Cr3+ was discussed. [source] | ||||||||||