Synthesis and IR Spectral Study of MoO2Cl2 Molecular Complexes with Acetoacetanilides. Crystal Structure of MoO2Cl2 Complex with Acetoacet-2-Toluidine

A series of MoO₂Cl₂ complexes with acetoacetanilide derivatives were synthesized and studied by IR spectroscopy. The crystal and molecular structures of the MoO₂Cl₂ complex with acetoacet-2-toluidine (HL) were determined by X-ray diffraction analysis. The monoclinic crystals involved are a = 7.621(7) Å, b = 9.498(3) Å, c = 19.980(9) Å, = 95.16(7)°, V = 1440(2) ų, Z = 4, and space group P2₁/n. The coordination polyhedron of the Mo atom is a distorted octahedron with two O oxoatoms in the cis-position relative to each other, two Cl atoms in the trans-positions, and two O atoms (HL) in the trans-positions to O(oxo).     

Quantum information processing and precise optical measurement with entangled-photon pairs

Two photons in a pair generated in the nonlinear optical process of spontaneous parametric down-conversion are, in general, strongly quantum entangled. Accordingly, they contain extremely strong energy, time, polarization and momentum quantum correlations. This entanglement involves more than one quantum variable and has served as a powerful tool in fundamental studies of quantum theory. It is now playing a large role in the development of novel information processing techniques and new optical measurement technologies. Here we review some of these technologies and their origins.     

Temperature Dependence of Integrated Intensity Bands in IR-Absoption Spectra of (NH4)2AF6 Complexes

The contribution refers to the temperature dependence of IR-absorption spectra (NH₄)₂AF₆ (A - Si and Ge). It is found that with temperature decreasing, the integrated intensities of the bands corresponding to anion fundamentals, increase, while those of cation, decrease. An explanation is given to the phenomena detected, which is based on variations in the strength of the outer-sphere interaction with the temperature, and subsequent redistribution of electron density.     

On one possibility of determining the atom position in the crystal unit cell

The possibility of the determination of the position of an atom incorporated in the crystal unit cell by measuring the yield of characteristic radiation of this atom, excited by an X-ray wave nonuniform over the cell cross section, is shown. Such a wave can appear, in particular, in the mode of dynamical diffraction of an ordinary plane wave.     

Aggregate stability and magnetic characteristics of colloidal Fe m O n –SiO2 particles obtained by sol–gel method

Physics of the Solid State - Composite Fe m O n –SiO2 particles have been obtained by precipitation of iron oxide from aqueous solution with the addition of tetraethoxysilane. The shapes and...     

Synthesis and study of the structure of cage-like metallosiloxanes with pair combinations of 3d transition and alkaline earth metals

The selective replacement of Na ions in cage-like (Cu,Na) organosiloxanes in reactions with divalent metal halides was studied. The sandwich-like isomer [PhSiO₂]₆Cu₄Na₄[PhSiO₂]₆ forms the corresponding bimetallic complexes [PhSiO₂]₆Cu₄M₂[PhSiO₂]₆ (M = Cu, Zn, Mg, Sr, Ba) retaining a sandwich-like structure (in 60–90% yields) regardless of the metal ion size in MCl₂. Under similar conditions, the reactions of the globular isomers [RSiO₂]₁₂Cu₄Na₄ (R = Ph, Me, Vin) with CuX₂ (X = Cl or Br) afforded insoluble polymer products. The reaction in dioxane or THF in the presence of DMSO gave the crystalline globular-type metal complexes [RSiO₂]₁₂Cu₄[CuX]₄, in which Na ions are replaced by CuX groups. The compositions and structures of the synthesized metal complexes were studied by X-ray diffraction, elemental analysis, and destructive silylation combined with gel permeation chromatography and ¹H NMR spectroscopy.     

Strategy for the synthesis of Di- and polymer tartratogermanates with single-charge cations. Crystal structures of K2[Ge2(OH)2(μ-Tart)2] · 4.5H2O and (NH4)2n [Ge2(μ-O)(μ-Tart)2] n · nMeCN · nH2O

Tartratogermanates of alkaline metals and ammonium are synthesized for the first time using different solvents (water, acetonitrile) and starting reagents (GeO₂ and GeCl₄): dimeric Kat₂[Ge₂(OH)₂(μ-Tart)₂] · 4.5H₂O (H₄Tart is D-tartaric acid, Kat = Na (I) and K (II)) and polymer (NH₄)_2n [Ge₂(μ-O)(μ-Tart)₂] _n · nCH₃CN · nH₂O (III). The complexes are characterized by elemental analysis, IR spectroscopy, and X-ray diffraction analysis. The structure of complex II contains binuclear isolated [Ge₂(OH)₂(μ-Tart)₂]₂-complexes. In complex III, the oxo ligands join the binuclear fragments into polymer chains.