In Situ Observation of Step Evolution on {100} Face of KH2PO4 Crystal in Solution by Atomic Force Microscopy (AFM)

In situ observation of the surface morphology of {100} face of Potassium Dihydrogen Phosphate (KDP) crystals growing in solution was made with the use of Atomic Force Microscope. The slight movement of the steps connected with regeneration of the crystal surface has been detected for very low supersaturation. The height of the elementary steps has been established.     

A detailed experimental and computational study of Cd complexes with pyridyl-based thiazolyl hydrazones

Interest in Cd complexes has been growing in recent years. Cd complexes are considered a potential solution in the search for novel antibiotics that can fight antimicrobial resistance. In addition, Cd complexes draw attention to material chemistry. The main objective of this work was to prepare the first Cd(II) complexes with anionic forms of pyridine-based thiazolyl hydrazone (THs) ligands HLS² [(E)-4-(4-methoxyphenyl)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)thiazole] and HLS³ [(E)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)-4-(p-tolyl)thiazole] and perform their structural and spectroscopic characterization, as well as stability in solution and upon heating. Studies related to their biological activities and possible electrochromic applications are also being conducted. Complexes [Cd(HLS²)₂] ( 1 ) and [Cd(HLS³)₂] ( 2 ) have been characterized by a single-crystal X-ray diffraction and computational analysis of intermolecular interactions responsible for their solid-state structures was performed. Thermal stability of 1 and 2 in the solid-state was analyzed by TGA/MS, where as their solution stability was determined by the spectrophotometric titration method. Electrochemical and in situ UV–Vis spectroelectrochemical analyses of 1 and 2 were carried out to determine redox mechanisms and the influence of the substituents and electrolytes on their redox responses. The antioxidant capacity of both complexes was tested in antioxidant assays, while their antimicrobial activity was tested against five Gram-positive and four Gram-negative bacteria, as well as against three fungi. The obtained results indicate their potent antioxidant capacity. The antimicrobial activity of investigated compounds on almost all tested bacterial strains was stronger than that of the standard antibiotic erythromycin. The results of docking studies indicate that the minor groove DNA is the possible biological target of 1 and 2 .     

Polymerization of glycolide promoted by ω-Al-alkoxide poly(ϵ-caprolactone) macro-initiators and formation of stable colloidal dispersions

Block polymerization of glycolide (GA) and ϵ-caprolactone (ϵ-CL) has been initiated with aluminum alkoxides, such as Al(OⁱPr)₃ and Et₂AlOCH₂X (where X = -CH₂-Br and -CH₂O-C(O)-C(Me)=CH₂), in THF at 40°C. Structure and composition of block copolyesters have been characterized with respect to the molecular weight by NMR spectroscopy and thermal analysis. Copolymerization is typically living, so that block copolyesters have been synthesized with predictable molecular weight and composition. The inherent insolubility of polyglycolide block is responsible for the heterogeneity of the polymerization medium and formation of stable, non-aqueous colloidal dispersions. This effect is especially pronounced at high GA/ϵ-CL molar ratios. Colloidal dispersions have been analyzed by transmission electron microscopy (TEM) and photocorrelation spectroscopy (PCS).