A theoretical study on the hydrolysis mechanism of carbon disulfide.

The hydrolysis mechanism of CS(2) was studied using density functional theory. By analyzing the structures of the reactant, transition states, intermediates, and products, it can be concluded that the hydrolysis of CS(2) occurs via two mechanisms, one of which is a two-step mechanism (CS(2) first reacts with an H(2)O, leading to the formation of the intermediate COS, then COS reacts with another H(2)O, resulting in the formation of H(2)S and CO(2)). The other is a one-step mechanism, where CS(2) reacts with two H(2)O molecules continuously, leading to the formation of H(2)S and CO(2). By analyzing the thermodynamics and the change in the kinetic function, it can be concluded that the rate-determining step involves H and OH in H(2)O attacking S and C in CS(2), respectively, causing the C=S double bond to change into a single bond. The two mechanisms are competitive. When performing the hydrolysis of CS(2) with a catalyst, the optimal temperature is below 252°C.