Quantum-chemical investigation of the reaction mechanism of 2-methylimidazole with 1,7-diiodo-2,2,6,6-tetramethyl-2,6-disilaheptane

Quantum-chemical investigation of the mechanism of reaction between 2-methylimidazole and 1,7-diiodo-2,2,6,6-tetramethyl-2,6-disilaheptane by the method B3LYP/6-311G(d,p) provided thermodynamic and kinetic characteristics of the formation channels of the new organosilicon fused and cyclophane structures whose yield depended on the ability of iodomethyl groups to be reduced at the action of HI formed in situ. On adding iodine that initiated the formation of triiodide anions the cyclic structures were stabilized as ionic liquids.     

Direct Comparison of DMA Damage, Isomerization of Urocanic Acid and Edema in the Mouse Produced by Three Commonly Used Artificial UV Light Sources

Exposure to sunlight can result in a number of harmful effects, including sunburn, erythema, premature aging of the skin, immune suppression and skin cancer. Studies designed to understand the underlying mechanisms often depend upon the use of artificial sources of UV radiation. Unfortunately, conclusions from different laboratories using different lamps often conflict, and it is entirely possible that the different spectra of sunlights used in each may be a source of conflict. To minimize confounding variables, we employed two of the more commonly used UV light sources, fluorescent sunlamps, such as the FS-40 and Kodacel-filtered FS-40 sunlamps, and a xenon arc solar simulator and compared, in one series of standardized experiments, the effects of each light source on DNA damage, urocanic acid isomerization and edema formation. The dose-response curves, calculated by linear regression or curve fitting were compared. The data indicate that DNA damage and urocanic acid isomerization were more sensitive to shorter wavelengths of UV than longer wavelengths, and the biological endpoint of edema most closely correlated with the induction of DNA damage. The results emphasize the dominance of shorter wavelengths within the UV spectrum in damaging biological tissues, even when the solar simulator, which contains significant amounts of UVA, was used and demonstrate that each light source has a characteristic pattern of induction of biochemical and biological endpoints.     

Synthesis and properties of polyamides from 2,5-furandicarboxylic acid and aromatic and aliphatic diamines

Russian Chemical Bulletin - Polyamides based on the 5-hydroxymethylfurfural derivative (2,5-furandicarboxylic acid dichloroanhydride) and diamines of both aromatic and aliphatic series were...     

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

The review is devoted to modern trends in the chemistry of 2-amino and 2-mercapto substituted benzothiazoles covering the literature since 2015. The reviewed heterocycles belong to biologically active and industrially demanded compounds. Newly developed synthesis methods can be divided into conventional multistep processes and one-pot, atom economy procedures, realized using green chemistry principles and simple reagents. The easy functionalization of the 2-NH₂ and 2-SH groups and the benzene ring of the benzothiazole moiety allows considering them as highly reactive building blocks for organic and organoelement synthesis, including the synthesis of pharmacologically active heterocycles. The review provides a summary of findings, which may be useful for developing new drugs and materials and new synthetic approaches and patterns of reactivity.     

Alkylation of C- and N-aminotriazoles with α-iodoketones

C- and N-Amino-1,2,4-triazoles react with 1-iodopropan-2-one in the absence of bases and phasetransfer catalysts (40°C, 9-12 h) to furnish 3-amino-1,4-bis(2-oxo-propyl)-4H-1,2,4-triazolium triiodide and 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium iodide. The alkylation of 1,2,4-triazol-4-amine with 1-iodopropan-2-one and 1,3-diiodopropan-2-one in the presence of elemental iodine led to the formation of 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium triiodide and 2-oxopropane-1,3-diylbis(4-amino-4H-1,2,4-triazolium) bis(triiodide). Triiodides are oily fluids possessing electric conductivity of 1.1 × 10^?3 Ω m^?1 opening the route to new types of electroconducting ionic liquids.     

Highly Unsaturated Macrocyclic Silahydrocarbons Containing Exocyclic Phenyl Groups

A series of 12- and 18-membered macrocycloethynes and macrocyclosilethenesilethynes, containing peripheral methyl and phenyl groups was prepared by organomagnesium sysnthesis under conditions of high dilution. One of these compounds contains an endocyclic 1,4-phenylene bridge.     

C- and Si-substituted benzyl(ethynyl)silanes

Hitherto unknown mono-, di, and triethynyl C- and Si-substituted benzylsilanes were synthesized by the reaction of benzylmagnesium halides with dialkyl(ethynyl)fluorosilanes and of benzyldichloro(hydrocarbyl) silane and benzyltrichlorosilane with ethynylmagnesium bromide. The IR and NMR spectra of all new compounds were studied.