Abstract
Vapor pressures of carbamate and thiocarbamate pesticides were estimated from their chemical structures by using the newly developed thermodynamic equations. The equations were derived from the modified Watson method by optimizing a parameter and introducing the concept of a number of possible hydrogen-bonding sites for better estimation of vapor pressures. This method could successfully estimate the vapor pressures of the tested pesticides and correctly predict vapor pressures, ranging from 10-5 to 101 Pa at 298K, of other pesticides not being utilized in the optimization procedure.
