Alternating polystannanes: synthesis, preparation, characterization and a computational study

Polystannanes have been synthesized by a number of useful routes. Generally, these polymers have been limited to homopolymers containing a single type of substituent. We now demonstrated a novel condensation polymerization utilizing dialkyl or diaryl tin dihydrides and dialkyl tin diamides to prepare alternating polymers with neighbouring tin centers possessing different group functionalities. Three new alternating polystannanes containing both organically solubilizing (n-Bu, Me) and less solubilizing (Ph) side groups as well as the homopolymer dibutylpolystannane have been prepared. A variety of closely related model tristannanes using the same synthetic methodology was also completed. We have also carried out a computational study of a number of model stannanes in order to optimize structures of the oligo- and polystannanes synthetically prepared and predict their spectral properties by using time dependent density functional theory (TD-DFT). This study has yielded results that can be influential in predicting chemical orientation, bonding properties and electronics.

Alternating polystannanes: synthesis, preparation, characterization and a computational study

Polystannanes have been synthesized by a number of useful routes. Generally, these polymers have been limited to homopolymers containing a single type of substituent. We now demonstrated a novel condensation polymerization utilizing dialkyl or diaryl tin dihydrides and dialkyl tin diamides to prepare alternating polymers with neighbouring tin centers possessing different group functionalities. Three new alternating polystannanes containing both organically solubilizing (n-Bu, Me) and less solubilizing (Ph) side groups as well as the homopolymer dibutylpolystannane have been prepared. A variety of closely related model tristannanes using the same synthetic methodology was also completed. We have also carried out a computational study of a number of model stannanes in order to optimize structures of the oligo- and polystannanes synthetically prepared and predict their spectral properties by using time dependent density functional theory (TD-DFT). This study has yielded results that can be influential in predicting chemical orientation, bonding properties and electronics.

Professional socialization of children in virtual museum space

The article analyzes the possibilities of competitive and exhibition activities in the virtual museum space for the development of professionally oriented interests and inclinations in children aged 7-14 years. A set of the most effective methods, techniques and forms of organizing competition and exhibition activities has been determined, a specially developed diagnostic toolkit has made it possible to analyze the experimental data obtained as a result of the use of empirical research methods: observation and survey. It was revealed that schoolchildren aged 7-14 are at different stages of professional maturity, from the stage of awakening (younger students) to the stage of professional socialization (younger adolescents). Experimental data have confirmed that competition and exhibition activities contribute to the development of creative thinking, self-actualization of the personality of schoolchildren. The huge educational potential of the competition and exhibition activity has been confirmed. The developed program of competitive and exhibition activities of a chemical orientation, contributing to the formation of professionally oriented interests and inclinations in children aged 7-14 years, will be useful to teachers, museum specialists.

DISEASE PROGRESSION POTATOES (SOLANUM TUBEROSUM L.) DURING STORAGE DEPENDING ON THE TERM OF PLANTING AND PROCESSING DRUGS BIOLOGICAL AND CHEMICAL ORIENTATION IN WESTERN POLISSYA

Application of biological preparations (Planriz, Fitotsid, Diazofit and Fosfoenterin) and chemicals (MC Ridomil Gold 68WG) in the conditions of Western Polissya has reduced the pathogens infection in 1.6–2.2 times at treatment of tubers prior to planting, plants during budding and flowering stages, as well as before storage. The least general disease development was observed in variants with Planriz (2.0–2.5 l/t), and the composition of biological preparation Planriz, Diazofit and Fosfoenterin (2.0–2.5 + 0.2 + 0.2 l/t). Among the total number of diseases the wet bacterial rot was 14.3–30.0%, Phoma exigua – 6.7–16.3%, Fusarium spp. – 62.5–71.1%. The development of Fusarium spp. has increased in 1.6 times at the end of storage period, Phoma exigua – in 4 times. The level of bacterial rot development had remained unchanged for the tubers of the Lileya cultivar planted in mid-May. The planting dates had almost no influence on the prevalence of disease at storage of the potatoes of Skarbnitsa cultivar.