Oxyhalogen-sulfur chemistry Kinetics and mechanism of the oxidation of cysteamine by acidic iodate and iodine
作者:Alice Chanakira、Edward Chikwana、David H Peyton、Reuben H Simoyi
DOI:10.1139/v05-263
日期:2006.1.1
cysteamine dimer (cystamine), with no further oxidation observed past this product. The stoichiometry of the reaction was deduced to be IO3 + 6H2NCH2CH2SH → I + 3H2NCH2CH2S-SCH2CH2NH2 + 3H2O in excess cysteamine conditions, whereas in excess iodate the stoichiometry of the reaction is 2IO3 + 10H2NCH2CH2SH → I2 + 5H2NCH2CH2S-SCH2CH2NH2 + 6H2O. The stoichiometry of the oxidation of cysteamine by aqueous
已在中性至弱酸性条件下研究了碘酸盐和碘水溶液对半胱胺的氧化。该反应相对较慢并且严重依赖于酸浓度。反应动力学是复杂的,并根据初始条件显示时钟行为、瞬态碘的产生,甚至碘的寡振荡产生。氧化产物是半胱胺二聚体(胱胺),没有观察到经过该产物的进一步氧化。反应的化学计量推导为 IO3?? + 6H2NCH2CH2SH → I?? + 3H2NCH2CH2S-SCH2CH2NH2 + 3H2O 在过量的半胱胺条件下,而在过量的碘酸盐中,反应的化学计量为 2IO3?? + 10H2NCH2CH2SH → I2 + 5H2NCH2CH2S-SCH2CH2NH2 + 6H2O。半胱胺被碘水溶液氧化的化学计量推导为 I2 + 2H2NCH2CH2SH → 2I?? + H2NCH2CH2S-SCH2CH2NH2 + 2H+。碘氧化半胱胺的双分子速率常数经实验评估为2.7(mol L≤≤1)≤≤1 s≤≤1。整体