Supramolecular organization of meso-substituted derivatives of tetraphenylporphine in thin films

Films of meso-substituted derivatives of tetraphenylporphine substituted in the paraor ortho-positions of the phenyl rings with alkoxy groups (-OC₄H₉ or -OC₁₆H₃₃) and films of their metal complexes are prepared using the Langmuir-Schaefer (LS) method. The effect of the molecular structure on the supramolecular organization of thin films is determined. The films are obtained by transferring layers of the compounds from the surface of the water onto silicon substrates using the Langmuir-Schaefer technique. The structures of the one-component LS films of the investigated compounds are studied by the small-angle X-ray scattering method, and also the lattice periodicities are calculated. The supramolecular organization of the meso-substituted tetraphenylporphine derivatives is modeled and refined by means of the X-ray diffraction method. When Ni or Cu serve as chelating metal, it is found that the macrocycle-macrocycle interaction is so large that it leads to violation of the molecular linearity, i.e., the lateral substituents are folded toward the macrocycle, reducing the area occupied by the structural units.     

Investigating the influence of a Forbush decrease on the detected flux of high-energy muons

The effect of Forbush decreases was studied for a flux of high-energy muons with a threshold of 220 GeV detected by the Baksan Underground Scintillation Telescope (BUST) of the Institute for Nuclear Research, Russian Academy of Sciences.     

Thermochemistry of Heteroatomic Compounds. Enthalpy of Dissolution and Vaporization of Selected Trimethylsilyl Di- and Tetrathiophosphates

Russian Journal of General Chemistry - Enthalpy of vaporization (ΔvapH°) of trimethylsilyl esters of dithio- and tetratiophosphoric acids (RX)2P(S)SSiMe3 (X = O, S) have been determined...     

Interaction of N,N'-Di(4-chlorophenyl)diimide 1,1'-Binaphtyl-4,4',5,5',8,8'-hexacarboxylic Acid with Thiourea Dioxide in Solution and Thin Film

Crystallography Reports - The reactions of interaction of N,N'-di(4-chlorophenyl)diimide 1,1'-binaphtyl-4,4',5,5',8,8'-hexa-carboxylic acid (cubogen red) with thiourea dioxide...     

Mesomorphism of thermotropic poly(propyleneimine) dendrimers and phase equilibria in systems on their basis

The thermotropic mesomorphism of poly(propyleneimine) dendrimers of first, second, and third generations has been studied by the methods of polarization thermomicroscopy and DSC. Phase diagrams for the binary systems of dendrimers with n-amyloxy-n′-cyanobiphenyl calamite liquid crystal and hexa(pentyloxy)triphenylene discotic liquid crystal have been constructed. Measurements have been carried out over the entire concentration range at temperatures corresponding to the stable states of nematic, columnar, and isotropic phases. The effects of the chemical nature and shape of linear and cyclic mesogen molecules on the manifestation of mesomorphism in LC dendrimers are considered.     

Structural,electrostatic and thermodynamic properties of the surface of spherical micelles in solutions of sodium <Emphasis Type="Italic">n</Emphasis>-alkyl sulfate homologues. I. Structural characteristics

Using the aggregation numbers of micelles and the effective sizes of hydrated surfactant ions and counterions of the first coordination sphere, we calculated the average geometric characteristics of the surface layer of ionic spherical micelles in solutions of the sodium n-alkyl sulfate homologues with n _C = 8, 10, 12, and 14 carbon atoms in the molecule; in particular, we established 1) the size of the micelle core; 2) the thickness of the electrical double layer on the surface; 3) the mutual arrangement parameters of hydrophilic and hydrophobic ions; 4) the number of “free” water molecules and showed their dependence on the homologue number and the degree of binding of counterions.     

Mesomorphic structure peculiarities of two mix-substituted phthalocyanines of the A3B type

Mesomorphic properties and structures of two mix-substituted lipophilic phthalocyanine derivatives of the A₃B type, with a different ratio of electron-donating (hexadecyloxy-) and electron-withdrawing (Cl-) substituents on the isoindol fragments ‘A’ and ‘B’, correspondingly, were studied by polarising optical microscopy, differential scanning calorimetry and small-angle X-ray scattering. Both compounds display columnar mesophases, and the type of organisation of the columns in the mesomorphic state was found to strongly depend on the number of peripheral chlorine substituents in the molecule. The di-chloro-substituted phthalocyanine forms a solid pasty lamellar phase at room temperature, which on heating undergoes successive transitions to two large-lattice columnar mesophases (2D-Col_h and 3D-M_Col) arising from the aggregation of several phthalocyanine-containing piles. On the contrary, aggregation of columns does not occur for the tetra-chloro-substituted phthalocyanine, which forms a nematic columnar mesophase of single phthalocyanine piles (1D-N_Col). While the di-chloro-compound partly crystallises on cooling, the nematic phase of the tetra-chloro-compound freezes at room temperature. The reasons for this different self-organisation behaviour are not yet fully understood, but some hints may be deduced from the proposed supramolecular models.     

A new method of synthesis of the B<Subscript>3</Subscript>H<Stack><Subscript>8</Subscript><Superscript>−</Superscript></Stack> anion

A new method of synthesis of the B₃H₈⁻ anion has been suggested. The method uses the reaction of some metal halides (CuCl, SnCl₂, CrCl₃, PbF₂, PbCl₂, PbBr₂, and BiCl₃) with sodium tetrahydroborate. It is characterized by high (up to quantitative) yields and simplicity of isolation of the target products ((n-C₄H₉)₄N)[B₃H₈] and Cs[B₃H₈].     

Formation and transformations of polyelectrolyte gel-ampholyte dendrimer-surfactant ternary complexes

The reactions of complex gels formed via the sorption of a poly(propylenimine) ampholyte dendrimer of the fourth generation by oppositely charged lightly cross-linked polyelectrolyte hydrogels with ionogenic micelle-forming surfactants have been studied. The sorption of surfactant ions likely charged relative to the complexed ampholyte dendrimer by complex gels is associated with two parallel chemical reactions controlled by the concentration of the surfactant and pH which give rise to the formation of network-dendrimer-surfactant tertiary complexes. The reactions of complex gels with surfactant ions likely charged relative to the network polyelectrolyte make it possible at different solution pHs to prepare both negatively and positively charged hydrogels reinforced by disperse particles of the dendrimer-surfactant complex.     

Colloid-chemical properties and physiological activity of water-soluble humic preparations

Conditions were found for solid-phase mechanochemical activation of coals, allowing a significant increase in the yield of water-soluble humic preparations enriched in humic acids and mineral elements. The humic preparations are characterized by a decrease in the molecular mass and by changes in the ionic composition and surface activity. The physiological activity of the humic preparations was determined.