THE RESEARCH OF THE STRUCTURE FORMATION PROCESSES OF DISPERSE MATERIALS AT THE OBTAINING OF THE COMPOSITE BUILDING MATERIALS WITH PREDETERMINED PROPERTIES

The basic concepts of the developed theory of the structure formation of dispersed materials in the preparation of composite building materials (CBM) with predetermined properties are proposed in the article. It is shown that, in addition to laborious methods of mathematical planning, low-cost research methods, for example, thermal methods, can be used to predict the properties of CBM. The data of differential scanning calorimetry, microscopic analysis, confirming the hypothesis that the thicknesses of water films on the surface of particles of disperse systems affect the formation of nano- and microstructures of CBM are presented. On the basis of VSTU in the center of collective use of the name of Professor Yu.M. Borisov conducted a number of tests on instruments of various domestic and foreign manufacturers, such as the RAULIKD derivative, the automatic diffractometer PANalytical EMPYREAN, the X-ray diffractometer DRON-2 and others using laser diffraction, synchronous thermal analysis. On the basis of the conducted experiments, the following conclusions were made: the IPFM systems with a phosphogypsum dihydrate content of 50 ... 60%, 10% lime, sandy loam 40 ... 30% possess the best physical-mechanical properties, water absorption and softening coefficients; drying at temperatures of 60 ... 65 ° C of the obtained materials leads to a decrease in the thickness of the water films between the particles and promotes further strength growth; an understanding of the mechanism of the effect of the thickness of aqueous films on the processes of the formation of hydrate hydrophilic systems allows us to predict that various technological methods leading to a reduction in their thickness will lead to an increase in the strength and other indices of materials obtained from non-flammable technologies.

Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine, IV [1]. X-Ray Structure Analyses of Trimethylpentylammonium-chloride and (4-Acetoxybutyl) trimethylammonium-iodide

The crystal structures of the title compounds which display cholinergic activity at the ganglionic receptor have been determined by X-ray structure analysis. [(CH3)3N+C5H11]Cl- (1) crystallizes in the orthorhombic space group Pbnm with half a formula unit per asymmetric unit, a = 11.381(14). b = 12.871(17), c = 7.316(4) Å. The intensities of 1106 independent reflections were collected with an automatic diffractometer. The structure refinement converged at R = 0.133 for the 355 observed reflections. The cation of 1 is disordered. [(CH3)3N + (CH2)4-O-C(O)-CH3]I- (2) crystallizes in the orthorhombic space group P212121 with four formula units per unit cell, a = 16.783(8), b = 10.276(6), c = 7.427(10) Å. The intensities of 1469 independent reflections were collected. The structure refinement converged at R = 0.071 for 1383 observed reflections. In both compounds the trimethylammonio methyl groups are coordinated nearly tetrahedrally by four anions in the first coordination sphere. Anions which occupy a special face type (B) of the tetrahedron of the (CH3)3N+ -CH2-group may be treated as a “model binding site” of the receptor. In the crystal structure of 2 the anions occupying B-type faces form together with the ammonium nitrogen and the carbonyl oxygen so called “Activity triangles”. The almost equal geometries of these activity triangles are correlated with the mode of pharmacological action.

Crystal structure of N,N′-dimethyl-2-imidazolidinethione, a by-product from the reaction of Na2(CH2N(CH3)CS2)2 and HgCl2

The reaction between mercury (II) chloride and N,N′-dimethylethylenebisdithiocarbamate gave a white precipitate. In an attempted recrystallization from an aqueous–ethanol solution, a cyclic thiourea-type compound, N,N′-dimethyl-2-imidazolidinethione, was obtained. The crystals of this compound are monoclinic, a = 10.388(2), b = 6.139(1), c = 12.291(4) Å, β = 118.64(2), and space group P21/c. The non-hydrogen atoms of the molecule are planar and the C=S bond length is 1.673(4) Å. The structure was refined by full-matrix least-squares from 642 independent reflections measured on an automatic diffractometer to R and Rw of 0.053 and 0.068, respectively.

The crystal and molecular structure of N,N′-ethylenebis(benzoylacetoniminato)-nickel(II)

The crystal structure of N,N′-ethylenebis(benzoylacetoniminato)nickel(II), NiII(benacacen), has been determined by X-ray diffraction. Crystals are monoclinic and belong to the space group P21/n; the cell dimensions are a = 793(2), b = 7.910(1), c = 22.020(4) Å, β = 96.68(2)°. Intensity data were measured on a four-circle automatic diffractometer and the structure was solved by combined use of direct and Patterson methods. Full-matrix least-squares refinement converged at R = 0.032 for 3456 observed reflections. The geometry around the Ni atom is square planar; remarkable planarity extends to the whole ligand, aside from the rotation of the phenyl rings and the torsion along the dimethylene bond. Bond distances and bond angles are in agreement with corresponding values found for other Schiff-base type complexes. The packing of the molecules leaves empty channels running through the crystal, a relevant point in the study of chemical models for oxygen carriers of biological interest.

The crystal structure of kogarkoite, Na3SO4F

SummaryThe crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

Etude structurale du monofluorophosphate de potassium K2PO3F

K2PO3F is orthorhombic, space group Pnma, with a = 7.554(4), b = 5.954(5), c = 10.171(6) Å, and Z = 4. Intensity data have been measured on an automatic diffractometer with CuKα radiation. The crystal structure was determined by analogy with that of K2SO4 and shows an important interaction "F---K". The final R index is 0.065 for 353 observed reflections.

The crystal and molecular structure of (4-diethylaminophenyl)diazenyltriphenylphosphonium tetrafluoroborate

The title compound crystallizes in the space group P21/c with four formula units in a cell of dimensions a = 10.146(6) Å, b = 10.593(4) Å, c = 26.31(1) Å, β = 103.14(3)°. Using 1496 observed reflections (I = 2.3σ(I)) in the range 0° < 2θ < 40° measured on a Picker FACS-1 automatic diffractometer with Mo-Kα radiation, the structure was solved (symbolic addition) and refined (full-matrix least-squares procedure) to R = 0.062 (Rw = 0.058), with all hydrogen atoms included and all non-hydrogen atoms having anisotropic thermal parameters. The dimensions within the cation are consistent with a delocalized electronic structure which is intermediate between valence formulations involving benzenoid or quinonoid structures for the (4-diethylaminophenyl)diazenyl residue. Some important bond lengths are N3—C22 1.336(7) Å, N2—C19 1.356(7) Å, N1—N2 1.308(6) Å, and P—N1 1.648(5) Å.