不确定楼主说的“不稳定”指的是什么意思。是“不稳定所以无法存在”还是“存在但是不太稳定”。高中化学更倾向于前者,所以在高中的推断题或书写同分异构体之类的题中一般不予考虑这种情况;实际呢是更倾向于后者,而化学竞赛或这大学化学的题目,是考虑它们的。一、连续两个碳碳双键的结构。C原子上同时连接2个碳碳双键,这种物质还是存在的,而且这类物质叫做积累二烯烃或联烯,对应的英文为allenes,最简单是丙二烯(propadiene)。见IUPAC对其的定义:allenesHydrocarbons (and by extension, derivatives formed by substitution) having two double bonds from one carbon atom to two others R2C=C=CR2. (The simplest member, propadiene, is known as allene).--------PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1314作为积累二烯烃的代表,丙二
...
继续阅读
(85)