The reaction coordinates for the opening and closing of the transannular bond in the 6 / 6 - closed and 5 / 6 - open isomers have been calculated . There is a shallow minimum corresponding to a 6 / 6 - open structure .

计算了两种异构体开 环与闭环过程的反应坐标， 发现 6/6开 环异构体是 势能 面上的一 局部最小点，而5/6闭环异构体不存在。