采用电位滴定法在DMSO/H_2O混合溶剂体系中测定磺酰脲(胺)类除草剂的酸离解常数

Acidity Constants of Herbicidal Sulfonylureas and Sulfonamides from Potentiometric Determinations in Aqueous Dimethyl Sulfoxide

采用电位滴定法在 DMSO/ H2 O(质量比 80∶ 2 0 )混合体系中测定了磺酰脲和三唑并嘧啶磺酰胺类除草剂的酸离解常数 ,进而采用回归分析方法探讨了测得的 p Ka 值与化合物的前沿轨道能级以及取代基效应之间的相关性 ,结果较为满意 ,从而证明从该体系测得的 p Ka

The acidity constants of herbicidal sulfonylureas and sulfonamides have been potentiometrically determined at 25 ℃ in DMSO/H 2O mixed solvent. The linear relationships between the experimental p K a values and the energy level of frontier orbital and substituent parameters have been found, which suggested that p K a values obtained from this mixed solvent were suitable for the structure activity relationships analyses.