A decanuclear [Dy 6 III Zn 4 II ] cluster: A {Zn 4 II } rectangle surrounding an octahedral {Dy 6 III } single molecule magnet

An octahedral {DyIII6} cage within a diamagnetic {ZnII4} rectangle is reported, with magnetic relaxation studies revealing single-molecule magnet behaviour for the complex under zero external dc field with Ueff = 43 K and to = 1 × 10-5 s

Electronic structure of a Mn-6 (S=4) single molecule magnet grafted on Au(111)

Contains fulltext : 72269.pdf (publisher's version ) (Open Access

Phenyl 2-pyridyl ketone and its oxime in manganese carboxylate chemistry: Synthesis, characterisation, X-ray studies and magnetic properties of mononuclear, trinuclear and octanuclear complexes

The use of phenyl 2-pyridyl ketone [(ph)(2-py)CO] and its oxime [(ph)(2-py)CNOH] in manganese benzoate chemistry has been investigated. The reaction of an excess of (ph)(2-py)CNOH with Mn(O2CPh) 2·2H2O affords the mononuclear complex [Mn II(O2CPh)2{(ph)(2-py)CNOH}2] ·1.2H2O (1·1.2H2O) in high yield. The MnII ion is coordinated by two monodentate benzoates and two N,N′-bidentate chelating (ph)(2-py)CNOH molecules in a cis-cis-trans fashion. The comproportionation reaction between Mn(O2CPh) 2·2H2O and NnBu4MnO4 (3:1) in the presence of (ph)(2-py)CNOH in MeCN/EtOH/CH2Cl2 leads to the isolation of the mixed-valent cluster [Mn8O 2(OH)2(O2CPh)10{(ph)(2-py)CNO} 4]· 4CH2Cl2 (2·4CH 2Cl2) in about 55% yield. A second synthetic procedure that leads to pure 2 involves the reaction between the known starting material (NnBu4)[Mn4IIIO2(O 2CPh)9-(H2O)] and four equivalents of the oxime ligand in CH2Cl2. The centrosymmetric octanuclear molecule contains four MnII and four MnIII ions held together by two μ4-O2- ligands and two μ3-OH- ions to give the unprecedented [Mn 8(μ4-O)2(μ3-OH) 2]14+ core, with peripheral ligation provided by ten PhCO2- (two η1, four syn,syn η1:η1:μ2 and four η1:η2:μ3) and four η1:η1:η1:μ2 (ph)(2-py)CNO- ions. The 1:1 reaction between Mn(O 2CPh)2·2H2O and the ketone (ph)(2-py)CO affords the trinuclear complex [Mn3(O2CPh) 6{(ph)(2-py)CO}2] (3) in more than 80% yield. As judged from single-crystal X-ray crystallography, the complex adopts a linear structure with one η1:η2:μ2 and two η1:η1:μ2 benzoates spanning each pair of metal ions. The terminal MnII ions are capped by bidentate chelating (ph)(2-py)CO ligands. The three complexes have been characterised by IR spectroscopy. The CV study of complex 2 in CH2Cl2 reveals irreversible reduction and oxidation processes. The magnetic properties of 2 and 3 have been studied by variable-temperature dc magnetic-susceptibility techniques. As the temperature approaches zero, the value of the χMT product for 2 approaches zero and, thus, the octanuclear complex has an S = 0 ground state. This S = 0 ground state is explained in terms of the magnetic behaviour of the central, butterfly-like [Mn4 III(μ3-O)2]8+ sub-core. The results for 3 reveal weak antiferromagnetic coupling, with J = -2.7 cn -1 for adjacent MnII ions. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004

Neutron spectroscopy and magnetic relaxation of the Mn6 nanomagnets

Inelastic neutron scattering has been used to determine the microscopic Hamiltonian describing two high spin variants of the high anisotropy Mn6 nanomagnet. The energy spectrum of both systems is characterized by the presence of several excited total spin multiplets partially overlapping the S 12 ground multiplet. This implies that the relaxation processes of these molecules are different from those occurring in prototype giant spin nanomagnets. In particular, we show that both the height of the energy barrier and resonant tunnelling processes are greatly influenced by low lying excited total spin multiplet

[Mn6] under pressure: a combined crystallographic and magnetic study

Folding under pressure: Crystallographic studies on a Mn6 single-molecule magnet under high pressure conditions show the drastic structural changes of the magnetic core (see picture, Mn purple, O red, N blue), which impact on the magnetic properties of ferromagnetic exchange between the metal atoms will be in booster weaker, and under extremely high pressure, a transition to antiferromagnetic behavior