Cyclopropane chemistry. Part 5 [1,2]. Hexafluorocyclopropane as a source of difluorocarbene
作者:J.Michael Birchall、Roy Fields、Robert N. Haszeldine、Reginald J. McLean
DOI:10.1016/s0022-1139(00)85225-2
日期:1980.6
yields of the corresponding 1,1-difluorocyclopropanes, formed by addition of difluorocarbene to the olefin. The tetrafluoroethylene formed dimerises to octafluorocyclobutane, co-dimerises with the olefin, or survives, depending on the reaction conditions. With allene, hexafluorocyclopropane gives 1-(difluoromethylene)cyclopropane, 2,2,3,3-tetrafluorospiropentane, and products derived from tetrafluoroethylene
Thermal unimolecular decomposition of 1,1,2,2-tetrafluorocyclobutane
作者:Robert T. Conlin、Henry M. Frey
DOI:10.1039/f19807600322
日期:——
9 kJ mol–1)/RT ln 10. The decomposition is almost certainly unimolecular and at the pressures studied the rate constants are close to their infinite pressure values. Rate constants were also determined from 22 to 0.01 Torr at 542.2 °C and the values obtained compared with those calculated using RRKM theory on the basis of various models. The energetics of the decomposition pathways are compared with
在气相中在485–593°C的温度范围内和5–9 Torr左右的压力下研究了1,1,2,2-四氟环丁烷的热分解。有两种均匀的一阶分解途径,一个分解途径生成1,1-二氟乙烯(k 1),另一个分解乙烯和四氟乙烯(k 2)。已为这些过程获得了Arrhenius方程,即。:log k 1 / s –1 = 15.34±0.05 –(292.0±0.8 kJ mol –1)/ R T ln 10 log k 2 / s –1 = 15.27±0.06 –(308.1±0.9 kJ mol –1)/ R Ťln 10.分解几乎可以肯定是单分子的,在所研究的压力下,速率常数接近于其无限大的压力值。还确定了速率常数,在542.2°C下为22至0.01 Torr,并将所得值与使用RRKM理论在各种模型基础上计算得出的值进行了比较。将分解途径的能量与环丁烷和氟化环丁烷进行比较。
Thermal decomposition of 1,1,2,2-tetrafluorocyclobutane at low pressures
作者:Ivy M. Bailey、Henry M. Frey
DOI:10.1039/f19817700709
日期:——
The relative rates of the two unimolecular decomposition channels have been determined as a function of pressure at 542.2 °C. These have been compared with RRKM calculations based on a step-ladder model for collisional energy transfer. The results are consistent with an average value of ΔE≈ 12 kJ mol–1.