Novel Synthetic Approach to the Blocksil Siloxane Copolymers

A novel synthetic approach to the block copolymers bearing diorganosiloxane and organosilsesquioxane blocks is suggested that obviates the need for using organochlorosilane precursors. A series of the polymers with different combinations of oligodimethylsiloxane and oligomethylphenylsiloxane flexible blocks with methylsilsesquioxane and phenylsilsesquioxane rigid blocks is prepared. The thermal properties of the films obtained from these polymers are explored.

Evaluation of the Sorption Capacity of a Maleic Acid Copolymer Towards Gold(III) Ions and Production of Catalytically Active Gold Nanoparticles on Its Base

Two spectrophotometric approaches are suggested for the assessment of the concentration of gold(III) cations in an aqueous solution: direct recording of the optical density of gold cations and galvanic substitution of silver atoms in polymer-stabilized silver nanoparticles with gold cations. The sorption capacity of a maleic acid copolymer towards gold cations is estimated. A colloidal composite containing gold nanoparticles is obtained from the polymeric gold salt. The catalytic properties of the resulting polymer-stabilized nanogold are studied in the aerobic oxidation of glucose to gluconic acid.

Optical Chemosensors for Cations Based on 1,8-Naphthalimide Derivatives

This review presents the examples of fluorescent sensors for metal cations based on a 1,8-naphthalimide optical platform and covers the main advances in this field for the last decade. The mechanisms of the generation of an optical signal are discussed in detail. Special attention is given to the authors' own works.

Recent Advances in the Synthesis of Isocoumarins and Polyaromatic Hydrocarbons for Photoactive Materials

The discovery of transition metal-catalyzed selective activation of aromatic carbon–hydrogen bonds in 1993 has opened a new era in the synthesis of carbo- and heterocyclic compounds. This review covers the applications of oxidative annulations of aromatic compounds with alkynes involving CH activation for the synthesis of isocoumarins and polyaromatic hydrocarbons (PAHs). The limitations, advantages, and mechanical aspects of this approach as well as the current tendencies in the application of the reaction products for photoactive materials are discussed.

Synthesis of bis-Heterocyclic Derivatives of Thiohydantoin

The possibility of structural modification of thiohydantoin derivatives via amidoalkylation under the action of a range of cyclic hemiamidals is demonstrated. The suggested approach provides, in particular, unsymmetrical nitrogen-containing bis-heterocyclic systems with pharmacologically relevant groups that are difficult to obtain by other methods.

Manganese Oxide Aerogels Obtained in a One-Step Process Directly in Supercritical CO2 at Different Temperatures

The work presents a study of the formation of manganese oxide aerogels in the process of thermal decomposition of manganese carbonyls in oxygen-enriched supercritical CO2 at different temperatures. The morphology of the aerogels was studied by means of electron microscopy; the porous structure was investigated through the analysis of low-temperature nitrogen adsorption/desorption isotherms. The process was observed in an optical high-pressure view-cell.

Trends in the Synthesis of Polyimides and Their Nanocomposites

This review presents the current achievements in the ecologically friendly synthesis of polyimides. The progress in the formulation and applications of different nanocomposites based on polyimides are highlighted. The enormous potential of the polymers and composites under consideration in environmentally benign synthesis and various application fields is shown.

Modification of Heterocycles by Amidoalkylation

The functionalized derivatives of heterocyclic compounds find extensive application in medicine, agriculture, and many fields of chemistry as precursors for more complex products that display remarkable biological and catalytic activities. A whole range of different heterocycles can be obtained by intra- or intermolecular amidoalkylation. This review presents the examples of successful application of the reactions of C-amidoalkylation, in particular, enantioselective reactions for the modification of heterocycles and outlines the prospects of their further application.

Metal Derivatives of Sulfonated Polyphenylquinoxaline

The polymer-analogous transformations of an aromatic ionogenic polymer, namely, sulfonated polyphenylquinoxaline afford a range of polymer salts bearing alkali (Li+, Na+, K+), alkaline earth (Mg2+, Са2+, Ba 2+), and transition di- (Cu2+, Ni2+, Zn2+) and trivalent (La3+, In3+) metal ions. The resulting polymers are characterized by elemental and thermogravimetric analyses. The solubility and rheological properties of their dilute and concentrated solutions as well as sensor properties of the coatings based on these polymer salts are explored.

Oligochitosan Hydrochloride: Preparation and Characterization

The methods commonly used for depolymerization of chitosan and preparation of oligochitosan are discussed. A synthetic approach to oligochitosan hydrochloride with a molecular weight below 16 kDa based on the treatment of parent industrial high molecular weight chitosan with a mixture of hydrochloric acid and hydrogen peroxide is described. A series of analytical protocols are used to determine the physicochemical properties and quality of resulting oligochitosan hydrochloride according to the European Pharmacopoeia 4.0.