coumaphos (10) and dichlofenthion (11) at 0.05 mol dm(-3) triethyl amine buffer, (s)(s)pH 10.8, 25 degrees C, under turnover conditions where the [phosphorothioate]/[9] ratio is 48.6, 13.4, 13.4, 18.6, and 48.6 respectively. In all cases, the products were derived from displacement of the leaving group by methoxide, the second-order turnover rate constants being 36.9, 0.45, 0.12, >146.7 and 44.3 dm3 mol(-1)
合成了邻
钯配合物Pd(dmba)(py)(OTf)(9)或Pd(N,N-二甲基
苄胺)(
吡啶)(
三氟甲磺酸盐),并研究了其在
甲醇中的溶液性质与pH的关系。在中性溶液中,
三氟甲磺酸酯从络合物中解离,形成显性形式的Pd(dmba)(py)(HOCH3),在酸性条件下,
吡啶解离,形成Pyr-H +和Pd(dmba)(HOCH3)(HOCH3)。在碱性条件下,Pd(dmba)(py)(HOCH3)电离产生Pd(dmba)(py)(-OCH3),
吡啶可从中解离,生成双甲氧基桥接的二聚体(Pd(dmba )(-OCH3))2(15-二聚体),及其单体Pd(dmba)(HOCH3)(-OCH3)。在缓冲条件下的动力学研究表明,9是杀fe
硫磷和其他P = S农药
甲醇分解的有效催化剂。催化剂的活性形式是碱性的,具有一种缔合的
甲醇盐,其表观(s)pK(a)为10.8。对UV / vis光谱随pH的变化进行分析,得出分光光度法(s)pK(a)为10