Reactivity and physical properties of π-conjugated hydrocarbon systems depend predominantly on the topology of π-electrons array. Quinoidal conjugations serve as giving diradical character to molecules, leading to unique chemical behaviors. The simplest member of quinodimethanes are o-, m-, and p-quinodimethanes, which are very reactive due to diradical character and cannot be isolated under normal experimental conditions. However, chemical modifications, such as π-extension or introduction of substituent groups, of quinodimethanes imparts stabilities to quinodimethanes that can be handled under ambient conditions. This chapter offers an overview of reactivity and magnetic properties of benzenoid o-, m-, and p-quinodimethanes.

π共轭碳氢化合物体系的反应性和物理性质主要取决于π电子阵列的拓扑结构。醌型共轭充当分子的双自由基特征，从而导致独特的化学行为。quinodimethanes的最简单的成员是ø - ，米- ，和p -quinodimethanes，这对双自由基字符非常具有反应性并且由于不能正常实验条件下分离。但是，喹啉甲烷的化学修饰，例如π-延伸或取代基的引入，使喹啉甲烷具有稳定性，可以在环境条件下进行处理。本章概述了benzenoid o-，m的反应性和磁性-和对-quinodimethanes。