Search results for "Bimetallic strip"

Dihydrogen complexes of metalloporphyrins: characterization and catalytic hydrogen oxidation activity

1992

A series of monometallic dihydrogen complexes of the type M(OEP)(L)(H{sub 2}) (M = Ru, Os; L = THF, *Im) was synthesized and characterized by {sup 1}H NMR. The H-H bond length was found to increase when Os was replaced by Ru or when *Im was replaced by THF. The bond distances (as determined by T{sub 1}) range from 0.92 to 1.18 {angstrom}. The first example of a bimetallic bridging dihydrogen complex, Ru{sub 2}(DPB)(*IM){sub 2}(H{sub 2}), was also prepared. The H{sub 2} ligand is simultaneously bound to both Ru-metal centers. High-field {sup 1}H NMR experiments (620 MHz) revealed a -7.37 Hz dipolar splitting of the H{sub 2} ligand for this complex. Analysis of this splitting suggests that th…

Single-crystal EPR study of the bimetallic ferrimagnetic chain MnCu(EDTA)·6H2O

1993

Abstract A single-crystal EPR study of the bimetallic chain compound MnCu(EDTA)·6H2O is reported. The angular dependence of the linewidth is discussed in relation to the magnetic dipole-dipole interaction, manganese zerofield splitting (ZFS) and copper hyperfine coupling. The calculation of the second moments indicates that ZFS is comparable to the dipolar contribution. The EPR data support the one-dimensional character of the compound.

Tantalocene complexes as bidentate métalloligands: (C5Me5)(C5H4X)Ta(H2)(PPh2) (C5Me5) (C5H4X)Ta(CO) (PPh2) (X = PPh2, CH2CH2NMe2)

1999

Abstract The synthesis of new bidentate metalloligands derived from tantalocene (C5Me5)(C5H4X)Ta(H2)(PPh2) (X = PPh2, 2P; X = CH2CH2NMe22N) and (C5Me5)(C5H4X)Ta(CO)(PPh2) 4(P,N) is described. When opposed to chromium unsaturated fragments the phosphino functionalised complexes 2P and 4P act as chelating bidentate ligands affording Ta(V) (C5Me5)(C5H4PPh2)Ta(CH2) (μ-PPh2)Cr(CO)4 or Ta(III) (C5Me5)(C5H4PPh2)Ta(CO)(μ-PPh2)Cr(CO)4 bimetallic complexes. The same reaction carried out starting from 2N gives rise to a μ-phosphido, μ-hydrido dibridged complex Cp*(C5H4CH2CH2NMe2)TaH(μ-H)(μ-PPh2)Cr(CO)4.

Design of chiral magnets: Cyanide-bridged bimetallic assemblies based on cyclohexane-1,2-diamine

2003

Abstract Four magnetic compounds based on chiral ligands trans-(1S,2S)-chxn and trans-(1R,2R)-chxn (chxn: cyclohexane-1,2-diamine), [Ni(trans-(1S,2S)-chxn)2]3[Fe(CN)6]2·2H2O (1), [Ni(trans-(1R,2R)-chxn)2]3[Fe(CN)6]2·2H2O (2), [Cu(trans-(1S,2S)-chxn)2]3[Fe(CN)6]2·4.5H2O (3) and [Cu(trans-(1R,2R)-chxn)2]3[Fe(CN)6]2·4.5H2O (4), are reported. The four compounds are chiral, as confirmed by X-ray analyses and circular dichroism measurements. From the magnetic point of view, 1 and 2 behave as ferromagnets, whereas 3 and 4 show a paramagnetic behavior.

Magneto-structural correlations in low dimensional ferrimagnetic systems

1991

The bimetallic compounds of the EDTA family provides a large diversity of ferrimagnetic model systems in which the dimensionality as well as the exchange-anisotropy can be controlled with ease. This paper deals with the magneto-structural chemistry of this family.

Modeling the magnetic properties and Mössbauer spectra of multifunctional magnetic materials obtained by insertion of a spin-crossover Fe(III) comple…

2013

In this article, we present a theoretical microscopic approach to describe the magnetic and spectroscopic behavior of multifunctional hybrid materials which demonstrate spin crossover and ferromagnetic ordering. The low-spin to high-spin transition is considered as a cooperative phenomenon that is driven by the interaction of the electronic shells of the Fe ions with the full symmetric deformation of the local surrounding that is extended over the crystal lattice via the acoustic phonon field. The proposed model is applied to the analysis of the series [Fe(III)(sal2-trien)] [Mn(II)Cr(III)(ox)3]·solv, in short 1·solv, where solv = CH2Cl2, CH2Br2, and CHBr3.

Structural diversity of cyanide-bridged bimetallic clusters based on hexacyanometallate building blocks

2002

Abstract Four new cyanide-bridged bimetallic complexes, with different geometries and nuclearities, have been synthesized and characterized by single crystal X-ray crystallography. The trinuclear compound {〚Zn(bpy)2(OH2)〛2〚Fe(CN)6〛}Cl (1)·2 MeOH·12 H2O crystallizes in the triclinic space group P 1 , with a = 12.010(2) A, b = 16.316(3) A, c = 16.325(3) A, α = 97.47(3)°, β = 92.14(3)°, γ = 92.43(3)°, V = 3166(1) A3 and Z = 4. The tetranuclear compound {〚Zn(phen)2〛2〚Fe(CN)6〛2}2– (2) cocrystallizes with 〚Zn(bpy)3〛2+ and 32 H2O molecules in the monoclinic space group C2/c with a = 42.047(8) A, b = 13.541(2) A, c = 28.781(5) A, β = 120.23(3)°, V = 14158(4) A3 and Z = 2. The pentanuclear compound …

Synthesis, Chirality, and Magnetic Properties of Bimetallic Cyanide-Bridged Two-Dimensional Ferromagnets

2006

The assembly of hexacyanoferrate(III) anions and nickel(II) bis-diamino complexes of the chiral ligand trans-cyclohexane-1,2-diamine (trans-chxn) yields cyanide-bridged two-dimensional ferromagnets of the general formula [Ni(trans-chxn)2]3[Fe(CN)6]2‚2H2O. Their crystal structure is built from cyanide-bridged bimetallic planes separated by the bulky chxn ligands, giving rise to a large interlayer distance ( d ) 11.7 A). These materials order ferromagnetically at the Curie temperature TC ) 14 K. AC susceptibility measurements evidence an unusual magnetic behavior below TC, with a marked frequency dependence. A thorough magnetic analysis demonstrates that this complex behavior is due to the pi…

Cobalt(II)-Copper(II) Bimetallic Chains as a New Class of Single-Chain Magnets

2004

Synthesis, characterization and crystal structure of the bimetallic cyano-bridged [(η5-C5H5)(PPh3)2Ru(μ-CN)Ru(PPh3)2(η5-C5H5)][PF6]

2005

Abstract The bimetallic cyano-bridged [(η 5 -C 5 H 5 )(PPh 3 ) 2 Ru(μ-CN)Ru(PPh 3 ) 2 (η 5 -C 5 H 5 )][PF 6 ] ( 1 ) was prepared by reaction of [(η 5 -C 5 H 5 )(PPh 3 ) 2 RuCl] with N , N ′-bis(cyanomethyl)ethylenediamine. The single crystal structure determined by X-ray diffraction showed crystallization on the triclinic P1 space group with a perfect alignment of the cyanide bridges. This accentric crystallization was explored having in view the NLO properties at the macroscopic level, determined by the Kurtz Powder technique. Besides the very low efficiency values for the second harmonic generation, the value obtained for the bimetallic complex 1 showed to be higher than one of the parent…