The specific rates of solvolysis of 2-adamantyl fluoroformate have been measured at 25.0 8C in 20 pure and binary solvents. These are well correlated using the extended Grunwald-Winstein equation, with incorporation of the N T solvent nucleophilicity scale and the Y Cl solvent ionizing power scale. The sensitivities (l ¼ 2.15 AE 0.17 and m ¼ 0.95 AE 0.07) toward the changes in solvent nucleophilicity and solvent ionizing power, and the k F /k Cl values are very similar to those previously observed for solvolyses of n-octyl fluoroformate, consistent with the addition step of an addition-elimination pathway being rate-determining. For aqueous ethanol, measurement of the product ratio allowed selectivity values (S) to be determined. The results are compared with those reported earlier for 2-adamantyl chloroformate and mechanistic conclusions are drawn.

Increased demand for plastics leads to a large amount of plastic manufacturing, which is accompanied by inappropriate disposal of plastics. The by-products of these waste plastics are microplastics (MPs; less than 5 nm in size), which are produced because of various environmental and physicochemical factors, posing hazardous effects to the ecosystem, such as the death of marine organisms due to the swallowing of plastic specks of no nutritional value. Therefore, the collection, preparation, identification, and recycling of these microsized plastics have become imperative. The pretreatment of MPs requires numerous chemical agents comprising strong acids, bases, and oxidizing agents. However, there is limited research on the chemical resistance of various MPs to these substances to date. In this study, the chemical resistance of five species of MPs (high-density polyethylene, low-density polyethylene, polystyrene, polyethylene terephthalate, and polypropylene) to sulfuric acid, hydrochloric acid, hydrogen peroxide, potassium hydroxide, and sodium hydroxide was studied. The MPs were reacted with these chemical reagents at preset temperatures and durations, and variations in morphology and chemical structures were detected when the MPs were reacted with mineral acids, such as sulfuric acid. The data pertaining to these changes in MP properties could be a significant reference for future studies on MP pretreatment with strong acids, bases, and oxidizing agents.

A kinetic study was carried out on the solvolysis of o-nitrobenzyl bromide (o-isomer, 1) and p-nitrobenzyl bromide (p-isomer, 3), and o-nitrobenzoyl chloride (o-isomer, 2) in a wide range of solvents under various temperatures. In all of the solvents without aqueous fluoroalcohol, the reactions of 1 were solvolyzed at a similar rate to those observed for 3, and the reaction rates of 2 were about ten times slower than those of the previously studied p-nitrobenzoyl chloride (p-isomer, 4). For solvolysis in aqueous fluoroalcohol, the reactivity of 2 was kinetically more reactive than 4. The l/m values of the extended Grunwald–Winstein (G–W) equation for solvolysis of 1 and 2 in solvents without fluoroalcohol content are all significantly larger than unity while those in all the fluoroalcohol solvents are less than unity. The role of the ortho-nitro group as an intramolecular nucleophilic assistant (internal nucleophile) in the solvolytic reaction of 1 and 2 was discussed. The results are also compared with those reported earlier for o-carbomethoxybenzyl bromide (5) and o-nitrobenzyl p-toluenesulfonate (7). From the product studies and the activation parameters for solvolyses of 1 and 2 in several organic hydroxylic solvents, mechanistic conclusions are drawn.

The specific rates of solvolysis of methyl fluoroformate have been measured at 40.0 o C in several hydroxylic solvents. Analysis with the extended Grunwald-Winstein equation leads to sensitivities toward changes in solvent nucleophilicity (l) of 1.33 ± 0.10 and toward changes in solvent ionizing power (m) 0.73 ± 0.06. For methanolysis, a solvent deuterium isotope effect of 3.98 is compatible with the incorporation of general-base catalysis into the substitution process. For four representative solvents, studies were made at several temperatures and activation parameters determined. These observations are also compared with those previously reported for alkyl halogenoformate esters and mechanistic conclusions are drawn.