4‐Phenyl‐1, 2, 4‐triazoline‐3, 5‐dione in the ene reactions with cyclohexene, 1‐hexene and 2, 3‐dimethyl‐2‐butene. The heat of reaction and the influence of temperature and pressure on the reaction rate. (17th January 2014)

• Record Type: Journal Article
• Authors: Kiselev, Vladimir D.; Kornilov, Dmitry A.; Kashaeva, Helen A.; Potapova, Lyubov N.; Konovalov, Alexander I.
• Is Part Of: Journal of physical organic chemistry. Volume 27:Number 5(2014:May)
• Page Start: 401
• Page End: 406
• Publication Date: 2014-01-17
• Subjects: Chemistry, Physical organic -- Periodicals; 547.1
• DOI: 10.1002/poc.3277
• Languages: English
• ISSNs: 0894-3230

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The values of the enthalpy (53.3; 51.3; 20.0 kJ mol<sup>−1</sup>), entropy (−106; −122; −144 J mol<sup>−1</sup>K<sup>−1</sup>), and volume of activation (−29.1; −31.0; −cm<sup>3</sup> mol<sup>−1</sup>), the reaction volume (−25.0; −26.6; −cm<sup>3</sup> mol<sup>−1</sup>) and reaction enthalpy (−155.9; −158.2; −150.2 kJ mol<sup>−1</sup>) have been obtained for the first time for the <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">ene reactions</named-content> of 4‐phenyl‐1, 2, 4‐triazoline‐3, 5‐dione <bold>1</bold>, with cyclohexene <bold>4</bold>, 1‐hexene <bold>6</bold>, and with 2, 3‐dimethyl‐2‐butene <bold>8</bold>, respectively. The ratio of the values of the activation volume to the reaction volume (∆<italic>V</italic><sup>≠</sup><sub>corr</sub>/Δ<italic>V</italic><sub><italic>r</italic> − <italic>n</italic></sub>) in the <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">ene reactions</named-content> under study, <bold>1</bold> + <bold>4</bold>→<bold>5</bold> and <bold>1</bold> + <bold>6</bold>→<bold>7</bold>, appeared to be the same, namely 1.16. The large negative values of the entropy and the volume of activation of studied reactions <bold>1</bold> + <bold>4</bold>→ <bold>5</bold> and <bold>1</bold> + <bold>6</bold>→<bold>7</bold> better correspond to the cyclic structure of the activated complex at the stage determining the reaction rate. The equilibrium constants of these <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">ene reactions</named-content> can be estimated as exceeding 10<sup>18</sup> L mol<sup>−1</sup>, and these reactions can be considered irreversible. Copyright © 2014 John Wiley & Sons, Ltd.</p> </abstract>