pH-controlled photoinduced electron transfer in the [(Mo6Cl8)L6]-calix[4]resorcine-dimethylviologen system

A pH-controlled photoinduced electron transfer in the supramolecular system [(Mo(6)Cl(8))L(6)]-calix[4]resorcine-dimethylviologen is reported.     

Novel Synthetic Route Toward Benzofuran-pyridine–Based Spirans

A novel domino reaction of tetrahydrobenzofuro[3,2-c] or [2,3-c]pyridines with dimethylacetylene dicarboxylate (DMAD) or methyl propiolate (MP) resulted in the formation of spirobenzofuranpyridines in moderate yields. The spirobenzofuran derivatives reported may be considered analogs of the antifungal drug griseofulvin.     

Investigating and optimizing electrophysical processes for joining tensomodule elements based on a silicon-on-insulator heterostructure by thermoelectrically stimulated bonding

The thermoelectrically stimulated bonding (in an electrostatic field) of the chip of a strain-sensitive pressure cell with a glass reference element to form the strain-sensitive module (tensomodule) of a thermally resistant pressure sensor is examined. The strain-sensitive pressure cell is based on a silicon-glass-silicon heterostructure.     

Study of the magnetic phase separation in the Eu0.65Sr0.35Mn1−x Fe x O3 ceramics by EPR and Mössbauer spectroscopy

Physics of the Solid State - The structural and magnetic properties of the Eu0.65Sr0.35Mn1?x Fe x O3 (x = 0.2–0.4) ceramics have been investigated using EPR, Mössbauer...     

Synthesis and properties of 4,5‐dihydrobenzo[e]imidazo[2,1‐c][1,4,2]diazaphosphinine derivatives

A number of 4,5‐dihydrobenzo[e]imidazo[2,1‐c][1,4,2]diazaphosphinine derivatives were prepared by the direct phosphorylation of 1‐(4‐Chlorophenylcarboxamido)‐2‐(1H‐1‐imidazolyl)‐5‐trifluoromethylbenzene in basic medium with phosphorus(III) bromide and dibromophenylphosphine. The tricyclic compounds 6a, 6b , and 9 having a trivalent phosphorus atom undergo the diazaphosphinine ring opening upon treatment with secondary amines in the presence of sulfur. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:84–92, 2002; DOI 10.1002/hc.10000     

ChemInform Abstract: Single-Crystal and Powder Neutron Diffraction Study of the FexMn1-xS Solid Solutions.

Single crystals of the α-MnS-based Fe_xMn_1-xS (x = 0-0.3) solid solutions are prepared and shown to be new Mott materials with the rock salt structure.     

Phosphorylation of 2‐(3‐methyl‐1,3‐diazabuten‐1‐yl)‐3‐ethoxycarbonylthiophenes with phosphorus(III) halides

2‐(3‐Methyl‐1,3‐diazabuten‐1‐yl)‐3‐ethoxycarbonylthiophenes are phosphorylated with phosphorus(III) halides in basic media at position 5 of the thiophene ring. Up to three heteroaromatic substituents can be introduced one by one at the same phosphorus atom. On this basis, mono‐, bis‐, and trishetaryl substituted P(III) and P(V) derivatives have been obtained. Phosphorylated 2‐(N,N‐dimethylformamidino)‐3‐ethoxycarbonylthiophenes provide a synthetic access to phosphorylated thienopyrimidines. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:641–651, 2001     

Heterocondensed 1,2,3‐diazaphosphorines

The reaction of phosphorus tribromide with phenylhydrazones of heterocyclic aldehydes leads to formation of a new phosphorus‐containing heterocyclic system—heterocondensed 1,2,3‐diazaphosphorines. Properties of the phosphorus‐containing heterocyclic compounds that have been synthesized are described. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:658–664, 2001     

A DFT quantum‐chemical study on the structures and active sites of polymethylaluminoxane

The electronic structure and geometry of polymethylaluminoxane (MAO) [—Al(CH₃)O—]_n with different size (n = 4–12) have been studied using quantum‐chemical DFT (density functional theory) calculations. It has been found: 1) Starting from n = 6, the three‐dimensional oxo‐bridged (cage) structure of MAO is more stable than the cyclic structure. 2) Both for cage structure and for cyclic structure the Lewis acidity of Al atoms characterized by their net positive charge amplifies with increasing size of MAO (n). 3) Trimethylaluminium (AlMe₃) reacts with the cage structure of MAO with cleavage of an Al‐O dative bond and formation of acidic tri‐coordinated Al^v and basic di‐coordinated O^v atoms in the MAO molecule. Two molecules AlMe₃ are associated with acidic Al^v and basic O^v centers. As the MAO increases in size, the acidity of Al^v centers amplifies and the distance Al^v‐(AlMe₃) shortens; on the contrary, interaction of AlMe₃ with O^v centers weakens and the distance O^v‐(AlMe₃) increases with increasing n value. The total heat of Al₂Me₆ interaction with MAO (sum interaction of Al^v‐(AlMe₃) and O^v‐(AlMe₃)) noticeably decreases as the size of MAO increases (from 50.9 kcal/mol for n = 4 to 20.2 kcal/mol for n = 12). It is proposed that acidic Al^v and basic O^v centers formed in the cage structure of MAO interact with zirconocene yielding ‘cation‐like’ zirconium active centers.