Four New Trinuclear {Cu3(μ3-OH)(oximate)3}2+ Clusters: Crystal Structure and Magnetic Behavior

Four new triangular copper(II) complexes with the fragment {Cu3(μ3-OH)(oximate)3}2+ and formulae [Cu3(μ3-OH)(μ-Cl)(Py2CNO)3(tBuPO3H)]·4H2O (1), [Cu3(μ3-OH)(μ-Br)(Py2CNO)3(tBuPO3H)]·3.5H2O (2), [Cu3(μ3-OH)(μ-Br)(PhPyCNO)3(tBuPO3H)(MeOH)]·1.5 MeOH (3), [Cu3(μ3-OH)Cl2(PhPyCNO)3]·0.5H2O (4), (Py2CNO = di(2-pyridyl)ketoximate, PhPyCNO = phenyl(2-pyridyl)ketoximate, tBuPO3H2 = tert-butylphosphonic acid) are reported. The magnetic properties of compounds 1-4 were studied. The compounds were found to exhibit strong antiferromagnetic coupling and antisymmetric exchange interaction

A Ferromagnetic Salicylaldoximate/Azide MnII2MnIII6 Cluster with an S = 17 Ground State and a Single-Molecule-Magnet Response

One new MnII 2MnIII 6 cluster exhibiting an S = 17 spin ground state and single-molecule-magnet properties has been designed linking MnIII 3-salicylaldoximate triangles and tetracoordinated MnII cations by means of end-on azido bridges. The ferromagnetic coupling has been rationalized as a function of their structural parameters

Field-Induced SMM and Visible/NIR-Luminescence Behaviour of Dinuclear LnIII Complexes with 2-Fluorobenzoate

The reaction of Ln(NO3)2·6H2O salts (Ln = Nd, Eu, Gd, Tb, Dy, Er and Yb) with 2-fluorobenzoic acid (H-2-FBz) and 1,10-phenanthroline (phen) in ethanol/water mixture allows the isolation of dinuclear compounds of the formula [Ln2(2-FBz)4- (NO3)2(phen)2] {Ln = Nd (1), Eu (2), Gd (3), Tb (4), Dy (5), Er (6)} and [Yb2(2-FBz)6(phen)2] (7). The solid-state photoluminescence study of the complexes shows the 4f-4f lanthanide transitions in the visible range, in the cases of 2, 4 and 5, and in the NIR range for 1, 6 and 7. Magnetic studies reveal field-induced single-molecule-magnet (SMM) behaviour for compounds 1, 5, 6 and 7

Dinuclear LnIII Complexes with 9‐Anthracenecarboxylate Showing Field‐Induced SMM and Visible/NIR Luminescence

The reaction of several Ln(NO3)3·6H2O salts with 9-anthracenecarboxylic acid (9-HAC) and 2,2′-bipyridine (bpy) in a mixture of CH3OH/H2O has allowed the isolation of the dinuclear compounds 1-6 with formula [Ln2(μ2-9-AC)4(9-AC)2(bpy)2] [LnIII = Nd (1), Eu (2), Gd (3), Tb (4), Er (5), and Yb (6)]. The molar magnetic susceptibility measurements of 1-6 in the 2-300 K temperature range indicate weak antiferromagnetic ex-. change for the isotropic GdIII compound 3. Compounds 1, 5, and 6 exhibit field-induced single-molecule magnet (SMM) behavior. The luminescence properties of compounds 1-6 in the solid state have been studied at different temperatures and show sensitization of the 4f-4f emission bands in the NIR range for compounds 1, 5, and 6

Circularly polarized luminescence on dinuclear Tb(III) and Eu(III) complexes with (S-) and (R-) 2-phenylpropionate

The reaction of Ln(NO3)(2)center dot 6H(2)O (Ln = Tb and Eu) with (S)-(+)-2-phenylpropionic acid (S-HL) and 1,10-phenanthroline (phen) in EtOH/H2O allows the isolation of the dinuclear chiral compounds of the formula [Ln(2)(S-L)(6)(phen)(2)]center dot 2.5 center dot S-HL in which Ln = Tb (S-1), Ln = Eu (S-2). The same synthesis by using (R)-(-)-2-phenylpropionic acid (R-HL) instead of (S)-(+)-2-phenylpropionic acid allows the isolation of the enantiomeric compounds with the formula [Ln(2)(R-L)(6)(phen)(2)]center dot 2 center dot 5 center dot R-HL where Ln = Tb (R-1), Ln = Eu (R-2). All compounds show sensitized luminescence. The luminescence study, including the circularly polarized luminescence spectra of the four compounds, is reported. The magnetic behavior of S-1 and S-2 is also reported

Chiral Dinuclear Ln(III) Complexes Derived from S- and R-2-(6-methoxy-2-naphthyl)propionate. Optical and Magnetic Properties.

The reaction of LnCl3·6H2O with (S)-(+)-2-(6-methoxy-2-naphthyl)propionic acid (S-HL), best known as naproxen, and 1,10-phenanthroline (phen) in EtOH allows the isolation of dinuclear chiral compounds S-1-4 of the formula [Ln2(S-L)6(phen)2]·3DMF·H2O [Ln(III) = Eu (1), Gd (2), Tb (3) and Dy (4)]. The use of the R-enantiomeric species of the HL ligand led to complexes R-1-4 with the formula [Ln2(R-L)6(phen)2]·3DMF·H2O. Compounds R- and S-1, 3 and 4 show strong sensitized metal-centred luminescence in the visible region. Moreover, Dy(III) complexes R- and S-4 display field-induced singlemolecule magnet (SMM) behaviour. For chiral and emissive compounds circularly polarized luminescence (CPL) measurements have also been performed

Assignment of aromaticity of the classic heterobenzenes by three aromatic criteria

Aromaticity is a key concept in physical organic chemistry. The aromatic order of the classic heterobenzenes was reported in experiment early. However, the unambiguous criteria used to validate the aromaticity of that were controversial or inadequate in theory. In this work, the global aromaticity of the compounds has been studied using the ELF, NICS and ISE. NICS(max)zz was calculated based on the maximum NICS contribution to the out-of-plane zz tensor component. Two types of bonds are observed. The correlations between NICS(max)σzz and NICS(max)πzz with respect to aromaticity are demonstrated, specifically between NICS(max)πzz and ELFπ (cc = 0.98) for π bonds. For σ bonds, the different electron delocalization of σ bonds out of the plane of the ring predicted well the discrepancies between NICS(max)σzz and ELFσ. The σ aromatic order of the classic heterobenzenes (C5H5N > C6H6 > C5H5P > C5H5As > C5H5Bi, C5H5Sb) was proved via the level of electronic delocalization