Synthesis of 7,7,8-Tris(alkoxycarbonyl)-8-cyanoquinodimethanes and Their Amphoteric Polymerization Behavior in Alternating Copolymerization

摘要

Unsubstituted 1,4-quinodimethane (QM) is so reactive that it gives polymeric materials immediately at room temperature. Introduction of electron-withdrawing substituents such as cyano and ester groups on its exocyclic carbon makes QM less reactive and crystalline materials may be obtained at room temperature: 7,7,8,8-tetracyanoquinodimethane, 7,7,8,8-tetrakis(methoxycarbonyl)quinodimethane, 7,7,8,8-tetrakis(ethoxycarbonyl)-quinodimethane, 7,8-bis(alkoxycarbonyl)-7,8-dicyanoquinodimethanes and so on. These isolable, electron-accepting quinodimethanes showed different polymerization behaviors depending on the nature and number of the electron-withdrawing substituents.