A spectrophotometric method was used to determine the acidity constant of 4'-carboxybenzo-24-crown-8 in 52% (w/w) ethanol-water mixture. The acid dissociation constant, Ka, was found to increase in the presence of Na+, K+, Rb+, Cs+ and Tl+ ions. The formation constants of the resulting 1:1 complexes between the carboxycrown a...

A computational study of the electronic structure and stability of complexes formed between Zeolite Y and boric acid was carried out at the HF and B3LYP levels using 6-31G* basis set. Five structures located as local minimum in PES of complex (structures d, e, f, g, and h). The most stable structure is formed due to hydrogen bonding between two hydroxyl of boric acid and both oxygen of ...

Humic acids extracted from different soils. The stability constants of metal humates and acid dissociation constant humic acids were calculated. Forms of metals in natural waters was determined with use account their chemical composition and content and properties of organic matter. We assessed metals speciation in water objects with account for competitive reactions resulting in formation of h...

Interaction of pure and Vn-doped (8, 0), (12, 0) and (16, 0) boron nitride nanotubes with CO molecules was studied using B3LYP/6-311++G(d) theoretical level. Substituting V instead of B atoms, increased the reactivity of nanotube. From the results, the complex stability depends on the direction and the number of the CO molecules interacted with the nanotube. In this work, the quantum...