Density functional theory (DFT) investigation of the oxidative degradation of NaAsO2 via hydroxyl radical

Arsenic is an environmentally ubiquitous health hazard due to its toxicity combined with natural abundance and heavy industrial applications. Due role in cardiovascular disease, neurotoxicity, various cancers, it important understand environmental fate of arsenic-containing compounds take steps towards remediation. Sodium arsenite (NaAsO2) one such compound that has been used worldwide as herbicide, rodenticide, insecticide. It also toxic by ingestion, inhalation, skin absorption. In aqueous environments, (As(III))-containing can be oxidized the less-toxic arsenate (As(V)) form. We have investigated oxidation sodium water solution at density functional theory level using Minnesota 06 hybrid (M06-2X) Pople basis sets (6-31G(d,p) 6-311G(d,p)) polarizable continuum model (PCM) solvation approach. Our computational results indicate mechanism NaAsO2 hydroxyl radical proceeds via sequential addition reactions where (III) converts (V) arsenic (IV) intermediate.