Pyrolysis of iodobenzene by the toluene carrier technique and determination of D[C₆H₅—I]

Abstract

. Can. J. Chem. 54, 2981Chem. 54, (1976.The pyrolysis of C6H51 has been studied by the toluene carrier technique over the temperature range 861-955 K using contact times of 0.54-3.28 s and total pressures of 2.5-4.13 kPa. Percent decomposition based on analysis for residual C6HjI ranged f r o n~ 5.6-93.3(t. Only trace quantities of 1 2 were observed and when HI mas trapped o~l t the only other gaseous products were small quantities of hydrogen and methane in about a 2:l ratio. Within the limits of the experimental method the decon~position was found to be homogeneous and first order.

Experimental and Theoretical Investigation of the Self-Reaction of Phenyl Radicals

“…In this work, we instead employ E 0 = 67.1 ± 0.3 kcal mol −1 , which was obtained from recent evaluations of the thermochemical data for C 6 H 5 I (Δ H r,0 = 42.2 kcal/mol) and C 6 H 5 (Δ H r,0 = 83.8 kcal/mol) by Ruscic, and is within the error bars suggested by Kumaran et al The fits to the present experimental data, Figure , now require a larger Δ E down = 800 cm −1 and a temperature-dependent η 0 = 0.04 T 0.19 , ∼0.16 over the range of the LS experiments. A consequence of the larger η 0 is that the extrapolated high pressure limit rate coefficient, k ∞ (Figure ), is increased by a factor of 2−2.8 over 1000−1800 K relative to that of Kumaran et al The experimental results of Robaugh et al lie about a factor of 3.6 lower than k ∞ and those of Kominar et al are about 50% lower. It has not been possible to produce a Gorin model that provides a satisfactory fit to the literature data and the current work by adjustments of E 0 , Δ E down , and/or η.…”

“…The rate coefficients for C−I fission, k 2a , as determined from the LS experiments are presented in Table and Figure , where they are compared with the experimental data from the literature ,– as well as with a restricted rotor Gorin model RRKM calculation. The present experimental k 2a values show little scatter and a clear pressure dependence which is predicted quite well by the Gorin model calculations.…”

“…Comparison of first order rate coefficients for the reaction C 6 H 5 I → C 6 H 5 + I. Part a shows current results and the experimental points from Kumaran et al Part b includes the lower temperature results of Robaugh and Tsang, Kominar et al, and Butler and Polanyi . The 22, 54, and 122 Torr RRKM calculations and experimental results of Kumaran et al have been removed for clarity.…”

Chemistry of Polycyclic Aromatic Hydrocarbons Formation from Phenyl Radical Pyrolysis and Reaction of Phenyl and Acetylene

“…A comprehensive analysis of the C–I fission in phenyl iodide decomposition has been performed by Tranter et al in their recent investigation of the self-reaction between phenyl radicals. The authors compared the experimental data present in literature − with their experimental results as well as the reaction rate constants obtained with a Gorin model RRKM calculation. It is not the purpose of the present work to repeat a detailed analysis of the thermal decomposition of phenyl iodide.…”

Palladium‐Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide

“…This indicates that the oxidative addition of the Pd‐catalyst into the C(aryl)−I bond of the aryl iodide starting material is more facile than the oxidative addition into the C‐Cl bond of the acid chloride product. Indeed, with 65 kcal mol −1 , the bond energy of C(aryl)−I is weaker than the bond energy of C−Cl (74 kcal mol −1 ) in acyl chlorides . Even though DIPEA as base showed good results in the chlorocarbonylation, 1,4‐diazabicyclo[2.2.2]octane (DABCO) proved to be superior in this case…”