Mechanism of Supplemental Activator and Reducing Agent Atom Transfer Radical Polymerization Mediated by Inorganic Sulfites: Experimental Measurements and Kinetic Simulations.

The mechanism of atom transfer radical polymerization (ATRP) mediated by sodium dithionite (NaSO), with CuBr/MeTREN as catalyst (MeTREN: tris[2-(dimethylamino)ethyl]amine)) in ethanol/water mixtures, was investigated experimentally and by kinetic simulations. A kinetic model was proposed and the rate coefficients of the relevant reactions were measured. The kinetic model was validated by the agreement between experimental and simulated results.

Explaining unexpected data via competitive equilibria and processes in radical reactions with reversible deactivation.

In the game rock-paper-scissors, each of the three options, or pathways, has an equal chance of dominating, that is, rock beats scissors, scissors beats paper, and paper beats rock. In the classical form of the game, there is no one dominant pathway to follow, but they are all balanced in likelihood. However, in chemical reactions with several competing reagents, the question must be asked, are all competing reactions and pathways accessible? A related question is, if there are two, or more reversible processes that compete for the same reagent, will both processes equilibrate simultaneously, or will one process dominate system? Can these competing processes shed light on otherwise puzzling data? Several unexpected and counterintuitive experiments have been reported in radical reactions with reversible deactivation.

Encapsulation of ammonium molybdophosphate and zirconium phosphate in alginate matrix for the sorption of rubidium(I).

Ammonium molybdophosphate and Phozir (alone or in combination) have been encapsulated in alginate beads for the synthesis of rubidium sorbents. SEM and SEM-EDX analyses confirm the homogeneity of the sorbents in terms of composition and metal binding. AMP sorbent is less sensitive to pH than Phozir, and optimum pH is close to pH 3 for the binding of Rb(I).