Single molecule magnet behaviour in a rare trinuclear {Cr(III)Dy} methoxo-bridged complex.

The reaction of the chromium(iii) chloride tetrahydrofuran complex with the dipivaloylmethane ligand, the lanthanide alcoholic salt DyCl3·CH3OH and the 1,1,1-tris(hydroxymethyl)-ethane ligand resulted in the formation of a new trinuclear chromium-dysprosium complex. Magnetic investigations revealed that the new 3d-4f complex exhibits single molecule magnet behaviour.

Tetrairon(III) single-molecule magnet monolayers on gold: insights from ToF-SIMS and isotopic labeling.

To work as magnetic components in molecular electronics and spintronics, single-molecule magnets (SMMs) must be reliably interfaced with metals. The organization on gold of a Fe4 SMM carrying two acetyl-protected thiol groups has been studied by exploiting the surface sensitivity of time-of-flight secondary ion mass spectrometry (ToF-SIMS), additionally powered by the use of an isotopic labeling strategy. Deposition from millimolar dichloromethane solutions results in a higher surface coverage and better packed monolayers as compared with previous protocols based on more diluted solutions.

Giant field dependence of the low temperature relaxation of the magnetization in a dysprosium(III)-DOTA complex.

The square antiprismatic Na[Dy(DOTA)(H(2)O)]·4H(2)O complex was characterised by single crystal X-ray diffraction and ac magnetic susceptometry. Two competing mechanisms for magnetic relaxation as well as the remarkable increase of six orders of magnitude in the relaxation time upon application of a static magnetic field were detected.

Catalytic enantioselective three-component hetero-[4+2] cycloaddition/allylboration approach to alpha-hydroxyalkyl pyrans: scope, limitations, and mechanistic proposal.

This article describes the design and optimization of a catalytic enantioselective three-component hetero-[4+2] cycloaddition/allylboration reaction between 3-boronoacrolein, enol ethers, and aldehydes to afford alpha-hydroxyalkyl dihydropyrans. The key substrate, 3-boronoacrolein pinacolate (2) was found to be an exceptionally reactive heterodiene in the hetero-[4+2] cycloaddition catalyzed by Jacobsen's chiral Cr(III) catalyst 1. The scope and limitations of this process were thoroughly examined.

Conformation of N(alpha)-substituted hydrazino acetamides in CDCl3, the precious help of the analysis of Deltadelta between amidic hydrogens, and correlation to the conformation of aza-beta3-peptides.

[structures: see text] We studied the conformation of a series of primary amides in a solution of chloroform. Classical NMR tools such as dilution experiments, influence of DMSO, and 2D-NOESY, together with X-ray diffraction, were combined with an analysis of the difference of the chemical shift Deltadelta between the geminal amidic protons. This study was addressed in order to understand the conformation adopted by hydrazino acetamides 1a and 1b as model compounds for aza-beta3-peptides.