Cleavage of B−C bonds and Anion [PhBH3]− Formation in the Reaction of the Yb(II) Hydride Complex with BPh3

Russian Journal of Coordination Chemistry - The reaction of the amidinatehydride complex of divalent ytterbium [(Amd)YbII(μ2-H)]2 (Amd is {tert-BuC(NC6H3-iso-Pr2-2,6)2}) with BPh3 proceeds...     

STEADY-STATE CREEP OF A LONG NARROW MEMBRANE INSIDE A HIGH RIGID MATRIX AT VARIABLE TRANSVERSE PRESSURE

Journal of Applied Mechanics and Technical Physics - This paper describes a problem of steady-state creep of a long narrow rectangular membrane in the case of a linear dependence between the...     

CaII,YbII and SmII Bis(Amido) Complexes Coordinated by NHC Ligands: Efficient Catalysts for Highly Regio- and Chemoselective Consecutive Hydrophosphinations with PH3

The first example of intermolecular hydrophosphination of styrene, 2-vinylpyridine and phenylacetylene with PH₃ catalyzed by bis-(amido) complexes [(Me₃Si)₂N]₂M(NHC)₂ (M=Ca, Yb, Sm) coordinated by NHC ligands is described. The reactions of styrene with PH₃ proceed under mild conditions in quantitative yields to afford only anti-Markovnikov product and allow for the chemoselective synthesis of primary, secondary and tertiary phosphines. Addition of phenylacetylene to PH₃ regardless the initial molar substrates ratio results in the exclusive formation of a tertiary tris-(Z-styryl)-phosphine. Crucial effect of the Lewis base coordinated to the metal ion in precatalyst on catalytic activity in styrene hydrophosphination with PH₃ was demonstrated. Free NHCs were also found to be able to promote addition of PH₃ to styrene, however they provide much lower reaction rates compared to the metal complexes.     

Highly Active,Chemo‐ and Regioselective YbII and SmII Catalysts for the Hydrophosphination of Styrene with Phenylphosphine

Stable heteroleptic amido Yb^II and Sm^II complexes bearing aminoether–phenolate ligands and devoid of coordinated solvent have been structurally characterized. They afford highly active, chemoselective and, in the case of monoadditions, 100 % anti‐Markovnikov regiospecific catalysts (down to 0.04 mol % loading) for the hydrophosphination of styrene with PhPH₂ under mild conditions.     

Dysprosium Single-Molecule Magnets with Bulky Schiff Base Ligands: Modification of the Slow Relaxation of the Magnetization by Substituent Change

The synthesis, and magnetic and photoluminescence investigations of two bifunctional dysprosium complexes based on tridentate Schiff base ligands is reported. Magnetic investigations reveal a genuine single-molecule magnet (SMM) behavior, with out-of-phase signals up to 60 K, and tunable emission arising from the Schiff base ligands.     

Non-linear constitutive relations for unstable materials

Non-linear constitutive relations to describe the rheological properties of unstable materials in the one-dimensional case are proposed, where the properties of instability, in particular ageing (i.e., the increase in stiffness and toughness of the material with time), are described by experimentally determined “instability functions”, which depend on the “age” of a given batch of material and, possibly, on invariance of the stress or strain tensors, which affect the rate of physical-chemical processes in the materials. Taking into account the instability of the material, a “fast” time is introduced, measured from the beginning of a short-term test with a material of a given age, and a “slow” time, measured from the instant when the material is produced. An exact solution of the problem of identifying the model, i.e., a determination of the material instability functions from experimental data, is constructed.     

Synthesis,Structure, Magnetic and Photoluminescent Properties of Dysprosium(III) Schiff Base Single‐Molecule Magnets: Investigation of the Relaxation of the Magnetization

We report here the synthesis, structure, magnetic and photoluminescent properties of three new bifunctional Schiff‐base complexes [Dy(L₁)₂(py)₂][B(Ph)₄]?py ( 1 ), [Dy(L₁)₂Cl(DME)] ? 0.5DME ( 2 ) and [Dy(L₂)₂Cl] ? 2.5(C₇H₈) ( 3 ) (HL₁=Phenol, 2,4‐bis(1,1‐dimethylethyl)‐6‐[[(2‐methoxy‐5‐methylphenyl)imino]methyl]; HL₂=Phenol, 2,4‐bis(1,1‐dimethylethyl)‐6‐[[(2‐methoxyphenyl)imino]methyl]). The coordination environment of the Dy³⁺ ion and the direction of the anisotropic axis may be controlled by the combination of the substituent groups of the Schiff bases, the nature of the counter‐ions (Cl^? vs. BPh₄^?) and the coordinative solvent molecules. A zero‐field slow relaxation of the magnetization is evidenced for all complexes but strong differences in the relaxation dynamics are observed depending on the Dy³⁺ site geometry. In this sense, complex 1 exhibits an anisotropy barrier of 472 cm^?1_, which may be favourably compared to other related examples due to the shortening of the Dy?O bond in the axial direction. Besides, the three complexes exhibit a ligand‐based luminescence making them as bifunctional magneto‐luminescent systems.     

A Double Addition of LnH to a Carbon-Carbon Triple Bond and Competitive Oxidation of Ytterbium(II) and Hydrido Centers

Addition of two Ln?H bonds of an Yb(II) hydrido complex supported by bulky amidinate ligand to a C?C bond lead to the formation of 1,2-dianionic bibenzyl fragment. Both Yb(II) and hydrido centers are oxidized under the reaction conditions. The resulting Yb(II) -η(6) -arene interaction is surprisingly robust: the arene cannot be replaced from the metal coordination sphere when treated with Lewis bases.