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1.
Chem Sci ; 10(10): 3065-3073, 2019 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-30996888

RESUMEN

The synthesis and characterization of a chiral, enneanuclear Mn(iii)-based, Single-Molecule Magnet, [Mn9O4(Me-sao)6(L)3(MeO)3(MeOH)3]Cl (1; Me-saoH2 = methylsalicylaldoxime, HL = lipoic acid) is reported. Compound 1 crystallizes in the orthorhombic P212121 space group and consists of a metallic skeleton describing a defect super-tetrahedron missing one vertex. The chirality of the [MnIII 9] core originates from the directional bridging of the Me-sao2- ligands via the -N-O- oximate moieties, which define a clockwise (1ΔΔ) or counter-clockwise (1ΛΛ) rotation in both the upper [MnIII 3] and lower [MnIII 6] subunits. Structural integrity and retention of chirality upon dissolution and upon deposition on (a) gold nanoparticles, 1@AuNPs, (b) transparent Au(111) surfaces, 1ΛΛ@t-Au(111); 1ΔΔ@t-Au(111), and (c) epitaxial Au(111) on mica surfaces, 1@e-Au(111), was confirmed by CD and IR spectroscopies, mass spectrometry, TEM, XPS, XAS, and AFM. Magnetic susceptibility and magnetization measurements demonstrate the simultaneous retention of SMM behaviour and optical activity, from the solid state, via dissolution, to the surface deposited species.

2.
J Am Chem Soc ; 140(31): 9814-9818, 2018 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-30040890

RESUMEN

We demonstrate that the [Yb(trensal)] molecule is a prototypical coupled electronic qubit-nuclear qudit system. The combination of noise-resilient nuclear degrees of freedom and large reduction of nutation time induced by electron-nuclear mixing enables coherent manipulation of this qudit by radio frequency pulses. Moreover, the multilevel structure of the qudit is exploited to encode and operate a qubit with embedded basic quantum error correction.

3.
Dalton Trans ; 46(18): 6024-6030, 2017 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-28426044

RESUMEN

Using a new polydentate Schiff-base ligand (H3L) we isolated three new tetranuclear isostructural lanthanide complexes with the general formula [LnNa2(L)4(DMF)4(H2O)2(AcO)2]·4DMF·2H2O [Ln = Dy (1), Ho (2), or Er (3)]. The structural characterization of the complexes reveals that the Na+ ions are coordinated in the structure which gives them a structure-directing role in the molecule. The magnetic behavior of the systems was investigated by means of SQUID magnetometry which revealed that complex 1 exhibits single molecule magnet behavior at low temperatures which is enhanced by the application of a 2000 Oe static magnetic field. We were able to extract an effective barrier of Ueff = 43(1) K, however, we show that the consideration of an Orbach relaxation mechanism being the dominant is not always correct for lanthanides. On the contrary, we elaborate how in this system the relaxation is caused by a combination of a direct and a Raman process.

4.
Inorg Chem ; 55(20): 10377-10382, 2016 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-27670363

RESUMEN

A tetranuclear [2 × 2] grid-like manganese(III) Schiff base complex, Mn4, has been synthesized and characterized by single-crystal X-ray crystallography. Direct-current magnetization measurements were performed on the system and proved to be insufficient for an accurate magnetic model to be deduced. Combined inelastic neutron scattering (INS) and electron paramagnetic resonance (EPR) experiments provided the necessary information in order to successfully model the magnetic properties of Mn4. The resulting model takes into account both the magnitude and the relative orientations of the single-ion anisotropy tensors.

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