Zum konzertierten oder nichtkonzertierten Verlauf von Reaktionen; Thermolyse von Dispiro[2.2.2.2]deca-4,9-dien

✍ Scribed by Roth, Wolfgang R. ;Unger, Christian

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Volume: 1995
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.1995199507181

✦ Synopsis

Concerted and Nonconcerted Reaction Path; Thermolysis of Dispiro[2.2.2.2]deca‐4,9‐diene

The enthalpy profile for the equilibrium 1 ⇄ 2 ⇄ 3 has been determined by oxygen trapping. From the oxygen dependence at low (0.0005–0.2 bar) and high pressure (1–180 bar) between 130 and 190°C the enthalpy wells of the diradicals 3 and 2 have been derived (3 17.1, 2 3.7 kcal · mol^−1^). The observation of a nonconcerted path for the equilibrium 1 ⇄ 3 is important with respect to the understanding of the controlling factor of the concerted and nonconcerted path of a reaction. The existence of a favourable potential energy path obviously is not of prime importance.