We report the determination of the absolute photoionization crosssection of cyclopropenylidene, c-C3H2, and the heat of formation of the C3H radical and ion derived by the dissociative ionization of the carbene. Vacuumultraviolet (VUV) synchrotron radiation as provided by the Swiss Light Source and imaging photoelectron photoion coincidence (iPEPICO) were employed. Cyclopropenylidene was generated
我们报告了环丙烯基的绝对光电离截面c -C 3 H 2的确定以及C 3的形成热H自由基和离子通过卡宾的解离电离而衍生。使用了由瑞士光源公司提供的真空紫外(VUV)同步加速器辐射和成像光电子重合技术(iPEPICO)。环丙烯叉基是通过四环烷烃前体与苯按1:1的比例热解生成的,这使我们能够从两种热解产物的光电离产率和已知的苯截面得出卡宾的接近阈值绝对光电离截面。例如,在9.5 eV处的横截面确定为4.5±1.4 Mb。在解离电离时,卡宾通过氢原子损失而分解为C 3 H +的线性异构体。确定该过程的外观能为AE 0K(c -C 3 H 2;l -C 3 H +)= 13.67±0.10eV。通过热化学循环从该值得出中性和阳离子C 3 H的形成热,为Δf H 0K(C 3 H)= 725±25 kJ mol -1和Δf H 0K(C 3 H +)=使用先前报告的C 3 H电离能,为1604±19 kJ
BUTLER, D. N.;GUPTA, I., CAN. J. CHEM., 1982, 60, N 4, 415-418
Quadricyclane-norbornadiene isomerizations on alumina
作者:Douglas N. Butler、Indranil Gupta
DOI:10.1139/v82-062
日期:1982.2.15
Standard synthetic steps have been used to convert 7-methylenequadricyclane into the spiro-cyclopropene 1 and the allene 2. These (and other) quadricyclanes are cleanly isomerized on alumina to the respective bicyclo[2.2.1]hepta-2,5-dienes 3 and 4.