Kinetische Untersuchungen zur Reaktion von Methylradikalen mit But-2-in

✍ Scribed by Dr. P. Claus; Dipl.-Chem. M. Marquardt; Dipl.-Chem. Tran Kim Trung; Prof. Dr. K. Scherzer

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 375 KB
• Volume: 332
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/prac.19903320418

✦ Synopsis

Kinetic Investigation of the Reactions of Methyl Radicals with But‐2‐yne

The reactions of methyl radicals with but‐2‐yne have been studied in a greaseless static vessel in the temperature range 543 ⃛583 K. The methyl radicals were generated by thermolysis of azomethane (initial pressures 2.66 kPa and 3.19 kPa) in mixtures with the alkyne (initial pressures 0 ⃛7,8 kPa). The primary steps are H‐abstractions producing 3‐methylpropargyl radicals and additions to the triple bond forming trimethylvinyl radicals. Both radicals were stabilized by hydrogen abstraction from the parent compounds and by combination processes. The temperature dependence of the rate constant k~2~ for the addition reaction can be expressed by the equation k~2~ = 10^8.65±0.20^exp (−40300 ± 1300)Jmol^−1^/RT M^−1^ s^−1^ For the rate constant k~1~ of hydrogen abstraction a value of k~1~ = 1,65 · 10^5^M^−1^ s^−1^ at 573 K was estimated. Therefore the H‐abstraction proceeds about two times faster than the addition reaction.