The thermal isomerization of cyclobutenes. XVI. 1,2‐bis(trimethylsiloxy)cyclobutene

The gas phase thermal isomerization of 1,2‐bis(trimethylsiloxy)cyclobutene has been studied in the temperature range 172°–204°C. The reaction is homogeneous, kinetically first order, and yields 2,3‐bis(trimethylsiloxy)buta‐1,3‐diene as the only product. The rate constants fit the Arrhenius equation\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {k = 10^{13.509 \pm 0.120} \exp \left( {{{ - 148,920 \pm 1060\,{\rm J}\,{\rm mole}^{ - 1} } \mathord{\left/ {\vphantom {{ - 148,920 \pm 1060\,{\rm J}\,{\rm mole}^{ - 1} } {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right)\sec ^{ - 1} } \hfill \\ {\left[ {k = 10^{13.509 \pm 0.120} \exp \left( {{{ - 35,590 \pm 250\,{\rm cal mole}^{ - 1} } \mathord{\left/ {\vphantom {{ - 35,590 \pm 250\,{\rm cal mole}^{ - 1} } {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right)\sec ^{ - 1} } \right]} \hfill \\ \end{array}$$\end{document}These results, taken with those obtained previously, demonstrate the insensitivity of the kinetics of the reaction to the nature of the groups substituted on the 1‐ and/or 2‐positions of the cyclobutene ring.