metallacyclopentadiene(alkyne) complex has been obtained. This type of metallacycle is believed to be the key intermediate in the cobalt-mediated [2 + 2 + 2]cycloaddition of alkynes. Thermal treatment leads to the generation of angular [4]phenylene, the X-ray structural details of which are described. Under photochemical conditions, the cobaltacycle isomerizes to a highly strained (cyclobutadieno)dibenzocyclooctatrienyne
[反应:见正文]已获得单核
金属
环戊二烯(炔)配合物的第一个X射线晶体结构。据信这种
金属环化合物是
炔烃在
钴介导的[2 + 2 + 2]环加成反应中的关键中间体。热处理导致生成角[4]亚苯基,对X射线的结构细节进行了描述。在光
化学条件下,
钴环异构化为高度紧张的(
环丁二烯)二苯并环辛
三烯复合物。