Search results for "Magnetochemistry"
showing 10 items of 10 documents
New Route to Polynuclear Ni(II) and Cu(II) Complexes with Bridging Oxime Groups That Are Inaccessible by Conventional Preparations
2019
A series of new polynuclear complexes of divalent Ni and Cu with 2-cyano-2-oximino-acetic acid (later AACO2-) were obtained as the result of the ligand modification reaction in the process of complexation, using 2-cyano-2-oximino-acetates such as methyl- (later as MeCO), and ethyl- (as ECO later on). Synthesized compounds were characterized by spectroscopic methods, thermal analysis, magnetochemistry, and X-ray crystallography. Crystal data revealed the formation of the dimeric [Ni(AACO)(H2O)3]2·H2O (1), trimeric K2[Ni3(AACO)4(H2O)4]·4H2O (2), and K2[Cu3(AACO)4(H2O)4]·4H2O (3) complexes, with bridging NO-groups cyanoxime dianions. In the latter two compounds, the AACO2– anions adopt cis-arr…
Magnetochemistry: From Fundamentals to Applications
2016
It is well knowm that Magnetochemistry is a multidisplinary area that deals with many different materials and properties. [...]
Triple bridged μ-phenoxo-bis(μ-carboxylate) and double bridged μ-phenoxo-μ1,1-azide/μ-methoxide dicopper(II) complexes: Syntheses, structures, magnet…
2013
Abstract The work in this paper presents syntheses, characterization, crystal structures, catecholase activity, electrospray ionization mass spectroscopy (ESI-MS positive), and magnetic properties of seven triple bridged μ-phenoxo-bis(μ-carboxylate) dicopper(II) complexes [CuII2L(μ-HCOO)2](ClO4)·CH3OH (1), [CuII2L(μ-CH3COO)2](ClO4) (2), [CuII2L(μ-CCl3COO)2(H2O)](ClO4) (3), [CuII2L(μ-CH3CH2COO)2](ClO4) (4), [CuII2L(μ-CH3CH2CH2COO)2](ClO4) (5), [CuII2L(μ-PhCOO)2](ClO4)·CH3CN (6) and [CuII2L(μ-o-ClPhCOO)2](ClO4) (7), one double bridged μ-phenoxo-μ1,1-azide system [CuII2L(μ1,1-N3)(N3)2] (8) and one double bridged μ-phenoxo-μ-methoxide system [CuII2L(μ-OCH3)(NCO)2] (9), derived from a new dinucl…
Special Issue 'Spin Crossover (SCO) Research'
2016
This special issue, entitled “Spin Crossover (SCO) Research”, illustrates the current relevance of a focused topic, which is inturn highly versatile. Indeed, the collection of papers presented constitutes a sampler that shows the topical importance of this area by attracting the interest of many top researchers and how it is approached under a multidisciplinary perspective.[...]
Molecular magnetism, quo vadis? A historical perspective from a coordination chemist viewpoint☆
2017
Abstract Molecular magnetism has travelled a long way from the pioneering studies on electron exchange and double exchange or spin crossover and valence tautomerism in small oligonuclear complexes, from mono- to di- and tetranuclear species, to the current investigations about magnetic anisotropy and spin dynamics or quantum coherence of simple mono- or large polynuclear complexes, behaving as switchable bistable molecular nanomagnets for potential applications in information data storage and processing. In this review, we focus on the origin and development of the research in the field of molecular magnetism from a coordination chemistry viewpoint, which dates back to the establishment of …
Metallosupramolecular approach toward multifunctional magnetic devices for molecular spintronics
2015
Abstract The work presented in this review constitutes a successful extension of our group's research on the chemistry and physics of dinuclear copper(II) metallacyclophanes with aromatic polyoxalamide ligands. The design and synthesis of metallacyclic complexes that contain multiple electro- and photoactive (either metal- or ligand-based) spin carriers and the study of their spectroscopic and magnetic properties as well as their redox and photochemical activity are of large interest in the multidisciplinary field of metallosupramolecular chemistry. In doing this, a ligand design approach has been followed which is based on the copper(II)-mediated self-assembly of bis(oxamato) bridging liga…
Synthesis, X-ray structure and magnetic properties of the azido adducts of quadridentate Schiff base manganese(III) complexes
2004
Abstract Two new azido derivatives of quadridentate Schiff base manganese(III) complexes have been synthesized and characterized structurally and magnetically. X-ray structure analysis revealed that both complexes viz. [Mn2(L1)2(N3)2] (1) and [Mn2(L2)2(N3)2] (2), where H2L1=N,N′-(1,1-dimethylethylene)-bis-(salicylaldiimine) and H2L2=bis(o-hydroxyacetophenone)-ethylenediimine exist as phenoxo-bridged dimer. The magnetic susceptibility of the complexes has been measured in the 5–300 K range. At room temperature the MnIII ions in complexes 1 and 2 possess an S=4 ground state. The global magnetic interaction in complex 1 is found to be ferromagnetic, while for complex 2 it is anti-ferromagnetic.
Prediction of Magnetic Properties in Oxovanadium(IV) Phosphates: The Role of the Bridging PO4 Anions
1998
Oxovanadium phosphates constitute a crystallochemically very rich family that, in turn, results in a seemingly intricate magnetochemistry including from isolated dimers to 3-D systems. This magnetic diversity is due, in part, to the possible participation of phosphate groups in the spin transfer between VIV centers. This way, 31P solid-state NMR becomes a key tool in determining the exchange paths involving phosphorus orbitals. The magnetic behavior of several layered oxovanadium phosphates M(VOPO4)2·4H2O (M = Na+, Ca2+, Ba2+, and Pb2+) has been investigated. Like it occurs in the case of other previously studied lamellar derivatives, the best fit of the temperature-dependent magnetic susce…
Structural, magnetic and related attributes of some oximate-bridged tetranuclear nickel(ii) rhombs and a dinuclear congenerElectronic supplementary i…
2003
New oximate-bridged tetranuclear nickel(II) complexes of compositions {Ni(Dien)}2(μ3-OH)2{Ni2(Moda)4}(ClO4)2·Solv (Solv = H2O, 1a; Solv = 2CH3NO2, 1b; Solv = 2H2O·2C4H8O2, 1c), {Ni(Sdien)}2(μ3-OH)2{Ni2(Moda)4}(ClO4)2·H2O (2), {Ni(Odien)}2(μ3-OH)2{Ni2(Moda)4}(ClO4)2·0.6H2O (3), {Ni(Dien)}2(μ3-OH)2{Ni2(Inaf)4}(ClO4)2·CH3NO2 (4) and {Ni(Odien)}2(μ3-OH)2{Ni2(Inaf)4}(ClO4)2·2NaClO4·2H2O (5) and the dinuclear complex (Ni{Odien})2(Moda)2(ClO4)2 (6) have been prepared (Dien = 1,5-diamino-3-azapentane, Odien = 1,5-diamino-3-oxapentane, Sdien = 1,5-diamino-3-thiapentane, ModaH = butane-2,3-dione monooxime, InafH = phenylglyoxaldoxime). X-ray examination revealed similar structures for 1a, 1b, 1c, 2 a…
Orbitally dependent kinetic exchange in cobalt(II) pairs: origin of the magnetic anisotropy
2003
Abstract A comprehensive theoretical study of the magnetic exchange between Co 2+ ions is reported. Using the microscopic background we deduce the general Hamiltonian for a corner-shared bioctahedral system involving kinetic exchange, spin–orbit coupling and low-symmetry local crystal field. This Hamiltonian acting within orbitally degenerate ground manifold 4 ( T 1g ) A ⊗ 4 ( T 1g ) B of the cobalt pair is expressed in terms of orbital and spin operators. We elucidate the major electronic factors controlling the exchange anisotropy in the Co(II) pairs. The degree of the magnetic anisotropy is shown to depend on the strength of the cubic crystal field and on the relative efficiency of two k…