Experimental Determination of Magnetic Anisotropy in Exchange-Bias Dysprosium Metallocene Single-Molecule Magnets.

We investigate a family of dinuclear dysprosium metallocene single-molecule magnets (SMMs) bridged by methyl and halogen groups [Cp' Dy(μ-X)] (Cp'=cyclopentadienyltrimethylsilane anion; 1: X=CH ; 2: X=Cl ; 3: X=Br ; 4: X=I ). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.

Design principle of half-sandwich type erbium single-ion magnets through crystal field engineering: a combined magnetic and electronic structure study.

To conclude the design principle for high-performance erbium-based single-ion magnets (SIMs), two half-sandwich type erbium complexes 1Er [(LOMe)Er(COT)] (LOMe = [(η5-C5H5)Co{P([double bond, length as m-dash]O)(OMe)2}3], COT = cyclooctatetraenyl) and 2Er [(THF)2(OAr)Er(COT)] (Ar = 2,6-Dipp2C6H3, Dipp = 2,6-diisopropylphenyl) were synthesized, and structurally and magnetically characterized. Both of them exhibited SIM behavior. Their magnetic relaxation behaviours were further elucidated by ab initio calculations and near-IR emission spectroscopy.

Two-Coordinate Co(II) Imido Complexes as Outstanding Single-Molecule Magnets.

The pursuit of single-molecule magnets (SMMs) with better performance urges new molecular design that can endow SMMs larger magnetic anisotropy. Here we report that two-coordinate cobalt imido complexes featuring highly covalent Co═N cores exhibit slow relaxation of magnetization under zero direct-current field with a high effective relaxation barrier up to 413 cm, a new record for transition metal based SMMs. Two theoretical models were carried out to investigate the anisotropy of these complexes: single-ion model and Co-N coupling model.

A new mass spectrometry electrospray tip obtained via precise mechanical micromachining.

A new electrospray tip incorporating a beveled edge has been designed for use in plastic electrophoresis chip/electrospray mass spectrometry. Theoretical hydrodynamic analysis has been conducted to model the analytical sensitivity of the spray tip shape. A larger sample wall, that provides increased hydraulic pressure, is recommended in order to preserve the fluid stability at the tip outlet.

Dead volume free micro-machined electro-spray chip for mass spectrometry.

Design and fabrication themes of a dead volume free electro-spray chip for mass spectrometry based on mechanical micro-machining approach is discussed in this article. To implement the dead volume free concept, a cantilever needle is embedded inside the micro-channel of the spray-chip such that there is no connecting joint between the sample wall and the spray-tip. To ensure that the proposed spray-chip is able to produce efficient Taylor cone, embedded needles with different cone angles are fabricated to produce an efficient experiment.