ESI-MS研究六钼酸盐芳香亚胺衍生物的合成反应及气相稳定性  

Study on Synthesis and Gas Phase Stability of Aromatic Imine Derivatives of Hexamolybdate by ESI-MS

作　　者：王倩倩 王海 史晓敏 WANG Qian-qian;WANG Hai;SHI Xiao-min(Fenyang College of Shanxi Medical University,Fenyang 032200,China;Second Hospital of Shanxi Medical University,Taiyuan 030000,China;School of Chinese Language and Literature,Shanxi Normal University,Taiyuan 030031,China)

机构地区：[1]山西医科大学汾阳学院,山西汾阳032200 [2]山西医科大学第二医院,山西太原030000 [3]山西师范大学文学院,山西太原030031

出　　处：《分析测试学报》2024年第2期322-327,共6页Journal of Instrumental Analysis

基　　金：山西医科大学汾阳学院引进人才启动基金项目(2022A09)。

摘　　要：该文通过合成两种Lindqvist型六钼酸芳香亚胺含氯衍生物TBA_(2)[Mo_(6)O_(18)(N-C_(6)H_(4)-Cl-p)](Ⅰ)和TBA_(2)[Mo_(6)O_(18)(N-C_(6)H_(4)-Cl-o)](Ⅱ),并采用电喷雾质谱法(ESI-MS)实时监测其合成反应过程,对两个反应体系中各物质含量随反应时间的变化趋势进行分析,考察了多酸芳香亚胺衍生物中芳香胺不同取代基的位置对衍生物合成反应速率及结构稳定性的影响。并通过碰撞诱导解离技术(CID)研究了两种衍生物离子的气相裂解反应,获得了其气相裂解途径及结构稳定性信息。ESI-MS实时监测结果显示,两种衍生物合成过程中,0~3 h内产物生成速率较小,而3~6 h期间反应速率最大,6~9 h次之,9~12 h反应速率明显减小。对氯苯胺的pKb小于邻氯苯胺,是衍生物Ⅰ的合成反应速率大于Ⅱ的重要原因。CID结果表明,相较于Ⅰ离子,Ⅱ离子的气相结构稳定性更弱,主要原因是Cl原子取代基的综合电子效应为吸电子效应,其在邻位取代比对位取代距离维系离子稳定性的Mo≡N键更近,导致Ⅱ中Mo≡N键电子云密度下降程度更大,离子的稳定性比Ⅰ更弱。综上,ESI-MS是一种研究多酸有机官能化衍生物的可靠技术,可为该类衍生物结构稳定性的研究及后期的导向设计合成提供基础信息。Organic aromatic amines in aromatic imine functionalized polyoxometalate derivatives have different substituent positions,to investigate its impact on the derivatives synthesis reaction rate and structural stability,two aromatic imines containing chlorine derivatives of Lindqvist type hexamolybdate were synthesized,they are TBA_(2)[Mo_(6)O_(18)(N-C_(6)H_(4)-Cl-p)](Ⅰ)and TBA_(2)[Mo_(6)O_(18)(N-C_(6)H_(4)-Clo)](Ⅱ).The reaction process was monitored in real time by electrospray ionization mass spectrometry(ESI-MS),the variation trend with reaction time of each species in the two reaction systems was analyzed,so as to study the effect of substituent position on the reaction rate.The gas phase cracking reactions of two derivative ions were studied through collision induced dissociation technique(CID),thus obtain on their gas phase cracking pathway and structural stability information.The ESI-MS realtime monitoring results showed,product generation rate is relatively low during 0-3 hours,while the reaction rate was the biggest during 3-6 hours,followed by 6-9 hours,and the reaction rate significantly decreased during 9-12 hours in the synthesis process ofⅠandⅡ.The pKb of p-chloroaniline is smaller than o-chloroaniline,which is an important reason why the synthesis reaction rate ofⅠis higher.The CID results indicate that compared to theⅠion,the gas-phase structural stability of theⅡion is weaker.The main reason is that the comprehensive electronic effect of the Cl atom substituent is the electron withdrawing effect,which is closer to the Mo≡N bond that maintains ion stability in ortho substitution than in para substitution.This leads to a greater decrease in the electron cloud density of the Mo≡N bond in theⅡion,and the stability of the ion is weaker than that of theⅠ.In summary,ESI-MS is a reliable technique for studying polyoxometalates organic functionalized derivatives,which can provide basic information for the study of structural stability and subsequent directed design and synthesis of such

关 键 词：电喷雾质谱法(ESI-MS) 六钼酸盐的芳香亚胺衍生物 取代基 合成反应 气相稳定性 

分 类 号：O657.7[理学—分析化学] O611.5[理学—化学]