【作者】 杨学良；

【导师】 陈从香；

【作者基本信息】 中国科学技术大学 ， 化学物理， 2005， 博士

【摘要】 本论文报道了我们对卤代卡宾自由基反应动力学的理论和实验研究。论文的第一部分主要是HCF自由基动力学的实验研究：（1）利用激光光解-激光诱导荧光技术对HCF（（?）¹A″）与直链烷烃和醇类猝灭动力学的实验研究；（2）利用激光光解-激光诱导荧光技术对HCF（（?）¹ A′）与一些小分子反应动力学的实验研究。论文的第二部分报道了我们利用量子化学理论和TST-RRKM理论对六个卡宾自由与NO以及HCF与C₂H₂和C₂H₄反应动力学的理论研究。 激发态HCF（（?）¹ A″）自由基猝灭动力学的实验研究： 利用213nm的激光光解CHFBr₂产生HCF自由基，用另一束波长为492.58nm的激光将HCF自由基从电子基态（?）¹ A′（000）态激励到激发态（?）¹ A″（030）态，通过检测处于激发态（?）¹ A″（030）的HCF辐射的时间分辨总包荧光信号，测定了室温下腔体压力为14.0Torr时直链烷烃和醇类分子对HCF（（?）¹ A″）自由基的猝灭速率常数，醇类和烷烃分子对HCF（（?）¹ A″）自由基的猝灭都是较为有效的，猝灭总包速率常数具有与“刚球碰撞模型”气动截面相当的数量级(10^-10cm³·molec^-1·s^-1)；随着猝灭剂分子中碳原子数的增加，HCF（（?）¹ A″）的猝灭速率常数及碰撞猝灭截面也线性增加。利用碰撞络合物模型计算了HCF（（?）¹ A″）与直链烷烃和醇类分子的碰撞络合物生成截面并与实验比较，发现计算结果与实验定性吻合。对实验结果与计算数据进行分析讨论，结果表明电子激发态HCF（（?）¹ A″）的猝灭过程可能属于多极吸引势起重要作用的入口通道控制机制，HCF（（?）¹ A″）对烷烃和醇类C-H键的插入反应在猝灭过程中起着重要作用。更多还原

【Abstract】 This dissertation presents the experimental and theoretical studies on the reaction kinetics of halocarbenes. The first part is mainly about the experimental studies on the kinetics of HCFradical: （I） the quenching kinetics of HCF（（A|^）1A"） by alcohol and alkane molecules using LP/LIF technique. （2） the reaction kinetics of HCF（（X|^）1A’） with some small molecules using LP/LIF technique. The second part is about the theoretical studies on the kinetics of six halocarbenes reaction with NO and HCF reaction with C₂H₂ and C₂H₄ using quantum chemistry methods and TST-RRKM theory.Time-resolved kinetic study on quenching of HCF（（A|^）1A"） using LP/LIF technique:The HCF radicals were produced by laser photolysis of CHFBr₂ molecules at 213 nm and were then excited from the ground electronic state to （A|^）1A" state with Nd: YAG laser pumped dye laser at 492.58 nm which is corresponding to the transition of （A|^）1A"（030）←（X|^）1A’（000）. The quenching rate constants k_q and thermally averaged cross section σ_q for collision quenching ofHCF（（A|^）1A"） state by normal alkane and alcohol molecules were measured at room temperature（298K） by observed the time-resolved fluorescence signals of the excited HCF in a cell at total pressure of about 14.0 Torr. Some regularity of the quenching rate constants with properties ofquenchers was obtained. It was shown that the quenching rate constants of HCF（（A|^）1A"） by the quenchers increase almost linearly with the number of C-H bonds contained in the homologous molecules. The formation cross sections σ_cf of the complex between HCF（（A|^）1A"） andquenchers were calculated by using collision complex model. The qualitative trendency of σ_cf is agreement with that of measured data. The results mean that the collisional quenching rates of HCF（（A|^）1A"） is probably controlled by the entranced channel, in which attractive forces via collision complex formation play an important role.更多还原