The thermal isomerization of tricyclo[4.1.0.0(2,7)]heptane and bicyclo[3.2.0]hept-6-ene was studied using ab initio methods at the multiconfiguration self-consistent field level. The lowest-energy pathway for thermolysis of both structures proceeds through the (E,Z)-1,3-cycloheptadiene intermediate. Ten transition states were located, which connect these three structures to the final product, (Z,Z)-1,3-cycloheptadiene. Three reaction channels were investigated, which included the conrotatory and disrotatory ring opening of tricyclo[4.1.0.0(2,7)]heptane and bicyclo[3.2.0]hept-6-ene and trans double bond rotation of (E,Z)-1,3-cycloheptadiene. The activation barrier for the conrotatory ring opening of tricyclo[4.1.0.0(2,7)]heptane to (E,Z)-1,3-cycloheptadiene was found to be 40 kcal mol(-1), while the disrotatory pathway to (Z,Z)-1,3-cyclohetpadiene was calculated to be 55 kcal mol(-1). The thermolysis of bicyclo[3.2.0]hept-6-ene via a conrotatory pathway to (E,Z)-1,3-cycloheptadiene had a 35 kcal mol(-1) barrier, while the disrotatory pathway to (Z,Z)-1,3-cyclohetpadiene had a barrier of 48 kcal mol(-1). The barrier for the isomerization of (E,Z)-1,3-cycloheptadiene to bicyclo[3.2.0]hept-6-ene was found to be 12 kcal mol(-1), while that directly to (Z,Z)-1,3-cycloheptadiene was 20 kcal mol(-1).

中文翻译：

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三环[4.1.0.0（2,7）]庚烷和双环[3.2.0]庚-6-烯通过（E，Z）-1,3-环庚二烯中间体进行热异构化。

使用从头算方法在多构型自洽场水平上研究了三环[4.1.0.0（2,7）]庚烷和双环[3.2.0]庚6-烯的热异构化。通过（E，Z）-1,3-cycloheptadiene中间体进行两种结构热解的最低能量途径。找到了十个过渡态，将这三个结构连接到最终产物（Z，Z）-1,3-环庚二烯。研究了三个反应通道，包括三环[4.1.0.0（2,7）]庚烷和双环[3.2.0]庚-6-烯的正反旋转开环和（E，Z）的反式双键旋转-1，3-环庚二烯。发现三环[4.1.0.0（2,7）]庚烷向（E，Z）-1,3-cycloheptadiene的旋转开环的活化势垒为40 kcal mol（-1），而向（Z，Z）-1，3-cyclohetpadiene计算为55 kcal mol（-1）。双环[3.2.0] hept-6-ene通过顺向旋转至（E，Z）-1,3-cycloheptadiene的热解具有35 kcal mol（-1）势垒，而向（Z，Z ）-1,3-cyclohetpadiene具有48 kcal mol（-1）的势垒。发现（E，Z）-1,3-cycloheptadiene异构化为双环[3.2.0] hept-6-ene的屏障为12 kcal mol（-1），而直接成为（Z，Z） -1,3-环庚二烯为20 kcal mol（-1）。