甲基羟基铀酰离子与水的复分解反应  

Metathetical Reaction of Organic Uranyl Species with Water in the Gas Phase

作　　者：胡斌[1] 陈兰慧[2] 郇延富[3] 张燮[1] 李明[3] 梁华正[1] 陈焕文[1] 

机构地区：[1]东华理工大学应用化学系,抚州344000 [2]东北师范大学化学学院功能材料研究所,长春130024 [3]吉林大学化学学院,长春130021

出　　处：《高等学校化学学报》2008年第5期912-915,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20505003)资助

摘　　要：以醋酸铀酰为主要试剂,在负离子检测模式下,采用电喷雾串联质谱法制备了甲基羟基铀酰负离子.实验发现,气相中的甲基羟基铀酰离子与水分子发生分子离子复分解反应,并用串联质谱法对反应产生的离子性产物进行了结构确认,提出了反应的可能机理.热力学计算结果表明,该反应的ΔGReaction为-473.0kJ/mol,ΔHReaction为-236.5 kJ/mol,ΔSSystem为0.792 kJ.mol-1.K-1.该反应的速率常数为2.26 s-1.Negatively charged organic uranyl species（ CH3UO2OH） was prepared and characterized with electrospray ionization tandem mass spectrometry implemented on an LTQ-MS instrument. Experimentally, it was found that ionic species of CH3UO2OH underwent metathetical reaction with water molecules present in the ion trap to produce negative ions of m/z 304 and a neutral methane species in the gas phase. The transient state of the reaction was observed and identified in the gas phase by tandem mass spectrometry. The mechanism was discussed in detail. The Gibbs free energy（△rG）, enthalpy（△rH） and entropy（△rS） for the reaction were calculated, on the basis of the experimental measurements, to be -473.0 kJ/mol, -236. 5 kJ/mol and 0. 792 kJ·mol^-1·K^-1 , respectively. The reaction rate constant was experimentally estimated to be 2. 26 s^-1.

关 键 词：气相复分解反应 醋酸铀酰 电喷雾质谱 碰撞诱导解离 分子离子反应 

分 类 号：O657[理学—分析化学]