modelling of chelate stabilized tetrylene derivatives.

The steric and electronic effects of specific ligands can play crucial roles in stabilizing unsaturated tetrylene species. In this work, hybrid density functional theory (DFT) methods, quantum theory of atoms in molecules (QTAIM) investigations and natural bond orbital (NBO) calculations are employed to evaluate the stabilization of low-valent E(ii) centers (E = Si, Ge, Sn, Pb) through the chelating effect generated by an electron-rich ligand containing the P[double bond, length as m-dash]C-P[double bond, length as m-dash]X moiety (X = O or S). Based on several types of analyses, such as the bond dissociation energy (BDE) or the interplay between attractive (, charge-transfer) and repulsive (, Pauli-exchange) effects, we highlight that the stabilization energy induced by chelation is up to 70 kcal mol for silylenes, yet slightly decreases within the heavier analogues.

Novel (Phenothiazinyl)Vinyl-Pyridinium Dyes and Their Potential Applications as Cellular Staining Agents.

We report here the synthesis and structural characterization of novel cationic (phenothiazinyl)vinyl-pyridinium (PVP) dyes, together with optical (absorption/emission) properties and their potential applicability as fluorescent labels. Convective heating, ultrasound irradiation and mechanochemical synthesis were considered as alternative synthetic methodologies proficient for overcoming drawbacks such as long reaction time, nonsatisfactory yields or solvent requirements in the synthesis of novel dye (E)-1-(3-chloropropyl)-4-(2-(10-methyl-10H-phenothiazin-3-yl)vinyl)pyridin-1-ium bromide and its -alkyl-2-methylpyridinium precursor . The geometry of the newly synthesized (E)-4-(2-(7-bromo-10-ethyl-10H-phenothiazin-3-yl)vinyl)-1-methylpyridin-1-ium iodide and (E)-1-methyl-4-(2-(10-methyl-10H-phenothiazin-3-yl)vinyl)pyridin-1-ium tetrafluoroborate was confirmed by single crystal X-ray diffraction.

Cytotoxicity and Antioxidant Potential of Novel 2-(2-((1H-indol-5yl)methylene)-hydrazinyl)-thiazole Derivatives.

Newly synthesized 2-(2-((1-indol-5yl)methylene)-hydrazinyl)-thiazole derivatives were evaluated for their in vitro cytotoxicity on two carcinoma cell lines A2780 and HeLa. Significant cytotoxic activity for 2-(2-((1-indol-5-yl)methylene)hydrazinyl)-4-methylthiazole () and 2-(2-((1-indol-5-yl)methylene)hydrazinyl)-4-phenylthiazole (), on both A2780 [IC: 11.6 μM (), and 12.