Reactivities of cis- and trans-buten-2-yl free radicals in presence of D2S. II. Absolute values of rate constants and isotopic effects

✍ Scribed by C. Richard; R. Martin

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 318 KB
• Volume: 17
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550170405

✦ Synopsis

Cis-and trans-buten-2-yl free radicals are shown to react with butene-2 cis (B,) and D2S in the following metathetical steps:

D

giving rise to butenes-1 (B1). The initial formations of butene-1,3 d, and total butene-1 in D2S-B, mixtures have been studied in the initial pressure range 20-200 torr for B,, 0-41 torr for D2S and a t 717-817 K. The main initiation and termination steps are shown to be: (t) 2 C4H,. -' products Assuming a rapid equilibrium between cis-and trans-C,H,., k, = exp(-85.5/RT) s -' ( R T i n kcal mol-') a n d k, = l O I 3 mol-' cm3 s-', we get: k Z c = 1.1 k 2 , = louo exp[(-9.25 ? 2)/RT1 mol-' cm3 s-l and k2 + 1.5 k2 = 10"' exp[(-15.2 2 2)/RTl mol-' cm3 s-*. Isotopic effects relating to processes (2c') + (2t') and t o (i') have been evaluated.