Molecular and electronic structure of halogen-substituted phosphaalkenes

Preparation of nanocomposite based on chitosan-PDCOEMA containing biosynthesized ZnO: Biological and thermal characterization

In this study, poly(2-(3,5-dichloroanilino)-2-oxoethyl 2-methylprop-2-enoate) (PDCOEMA), a new synthetic polymer based on methacrylate, was synthesized and characterized. The blend of PDCOEMA with chitosan (CS) was prepared by the hydrothermal method and the DSC technique confirmed its formation. It was observed that PDCOEMA increased the thermal stability and glass transition temperature (Tg) of CS. The Tg value of the PDCOEMA-CS blend was increased at about 7 °C with the highest ZnO NPs contribution rate. PDCOEMA-CS/ZnO nanocomposites were prepared by adding ZnO NPs produced by biosynthesis at different weight ratios to the PDCOEMA-CS blend by hydrothermal method. When the thermal stability of nanocomposites determined by TGA was examined, it was observed that it increased significantly compared to CS. While the initial decomposition temperature of CS was 270 °C, this value increased to 293 °C after blending with DCOEMA, and to 317 °C with the addition of 7 % ZnO NPs. Antimicrobial, anticancer, cytotoxic, antioxidant, and wound healing properties of PDCOEMA, CS, PDCOEMA-CS blend, and nanocomposites were determined. According to the obtained results, it was observed that nanocomposites containing 5 % and 7 % ZnO NPs showed good anticancer activity against A549 cells at a dose of 10 μg/mL. The results show that the produced nanocomposites can contribute to developing CS-based materials.

Molecular structure of 1-(2,4,6-tri-tert-butylphenyl)-4,4-bis(dimethylamino)-1-aza-2,3λ3-phosphabutadiene-1,3

The crystal and molecular structure of 1-(2,4,6-tri-tert-butylphenyl)-4,4-bis(dimethylamino)-1-aza-2,3λ3-phosphabutadiene-1,3, Ttb-N=P-P=C(NMe2)2, has been determined (crystal data of C23H41N3P, C2/c; Z=8, monoclinic, a = 17.252(7), b = 9.014(3), c = 32.095(8) Å, β = 94.00(3)). The main geometrical parameters of 1 are: N=P 1.582(5), P-P 2.130(3), P=C 1.808(6) Å, CNP 123.8(4), NPP 111.6(2), PPC 94.1(2), CNPP -0.7, NPPC 176.8o. Peculiarities of the molecular structure 1 (in particular, significant shortening of P-P single bond and realization of C-N=P-P bonds system in sterically unfavourable cis-form) are discussed on the basis of ab initio calculations of the model phosphabutadiene systems.