Reactions between 1-Ethynylazulenes and 7,7,8,8-Tetracyanoquinodimethane (TCNQ): Preparation, Properties, and Redox Behavior of Novel Azulene-Substituted Redox-Active Chromophores
Cycloaddition/cycloreversion reactionsbetween TCNQ and mono- or bis[2-(azulen-1-yl)ethynyl]benzene or -thiophene derivatives were examined: the corresponding TCNQ adducts, novel azulene-substituted redox-active chromophores, were produced in excellent yields. TCNE/TCNQ double adducts were also prepared both by stepwise and by one-pot cascade reactions. The redox behavior of these novel azulene-substituted