Addition-curable type liquid silicone rubbers based on phenyl-containing organopolysiloxanes with terminal vinyl groups

Russian Chemical Bulletin - A series of organosilicon rubbers of the addition-curable type containing dimethyland methylphenylsiloxy, or diphenylsiloxy units with terminal vinyl groups were...     

X-ray analysis of powdered celluloses obtained with the use of Lewis acids

It is established via an X-ray method that the preparation of powdered forms of cellulose under the action of Lewis acids on fibrous hardwood cellulose is accompanied by a change in its crystallographic characteristics. The degrees of crystallinity, the sizes of crystallites, and the periods and monoclinic angles of the unit cells of the obtained powdered celluloses were determined.     

Spectroscopic study of interaction of 1H-1,2,4-triazoline-3-thione with molecular iodine

The formation by 1H-1,2,4-triazoline-3-thiones in dilute chloroform solution of n-σ*-complex with molecular iodine of the composition C₂H₂N₃S·I₂ was studied by electronic spectroscopy in the UV and visible regions (log β = 2.14±0.05). By the XRD method the crystal and molecular structure of the product of chemical interaction of the thione with molecular iodine in ethanol, 1,2-di(1H-1,2,4-triazol-3-yl) disulfide, was determined.     

Influence of mechanoactivation on the perovskite structure

The crystal structure of the perovskite rhombohedral modification before and after mechanoactivation in air and in carbon dioxide is studied using the X-ray diffraction method. It is shown that a medium in which an as-grown perovskite crystal is milled influences the degree of its amorphization but does not influence either the size of ordered areas or the distortion of titanium and calcium coordination polyhedra. It is found that the rate of perovskite milling is smaller than the rate of pseudowollastonite milling under the same conditions.     

Reaction of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine

Russian Chemical Bulletin - The formation of the n-σ* complex of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine of the composition C3H4N2S2·I2 in dilute chloroform solutions...     

A Mercury-free Electrode for Determining Amalgam-forming Elements by Stripping Voltammetry

A mercury-free modified screen-printed electrode was proposed for the preconcentration and determination of Cu(II), Pb(II), Cd(II), and Zn(II). The simplicity of design, compactness, and low cost of the developed electrode; the possibility of using it as a disposable electrode; and no need in any operations on the mechanical treatment of the electrode surface make this electrode a candidate for portable transducers in flow and discrete analyses.     

Solvent mediated reaction of 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-tetrazoline-5-thione with iodine

1-Methyl-1H-tetrazoline-5-thione (1) reacts with iodine in CHCl₃ with formation of 1:1 stable σ-complex (logβ = 3.8 ± 0.1 is found by spectrophotometry). In the ethanol solution irreversible oxidation with formation of disulfide product 5,5′-dithiobis(1-methyl-1H-tetrazole) (2) is observed. The structure of (2) was determined by X-ray diffraction. Strong intermolecular interactions with shortened contacts are observed between sulfur atom of disulfide bridge and heterocyclic nitrogen of the neighboring molecule (S···N 3.0179(15) Å) forming infinite supramolecular chains which are further linked with π–π stacking interaction of tetrazole rings (interplane distance is 3.1685(6) Å).     

Fluorination of the cubic and hexagonal C60 modifications by crystalline manganese trifluoride

This paper reports on a comparative study of the solid-state fluorination of the cubic and hexagonal fullerene C₆₀ modifications by crystalline manganese trifluoride. It is shown that the variation of the fullerene crystal structure does not noticeably affect the composition of the fluorination products. The enthalpy and entropy of sublimation of the C₆₀ hexagonal phase are experimentally determined for the first time.     

Optical and X-ray imaging analysis of chemical elements associated with microbial communities

We analyze the distribution of chemical elements in microbial communities from various hydrothermal ecosystems (the Kurile-Kamchatka volcanic belt, the Baikal rift zone) and various laboratory cultures by means of microXFA-SR. We describe various techniques for combining optical and microXFA-SR X-ray cell images. The combination of images allows us to demonstrate the accumulation of chemical elements in cells of bacteria, cyanobacteria, and diatom and green algae.     

Yield and quality of bacterial cellulose from agricultural waste

Cellulose - The global abundance and availability of oat hulls make them a promising feedstock to produce a unique type of cellulose, the bacterial one. This is the first study examining how a...