Ferrocenyl substituted calixarenes: synthesis, structure and properties

Abstract

A set of ferrocenyl substituted calix[4]arenes were designed and synthesized by the Pd-catalyzed Sonogashira cross coupling reaction. The photophysical and electrochemical data show a substantial electronic interaction between the ferrocene unit and the calixarene core. Calixarenes 5a–5c are non-emissive in nature and the absorption maxima of 5a–5c exhibit a red shifted absorption. The calixarene core exhibits a cone conformation, which was confirmed by ¹H NMR and X-ray crystallography. The crystal packing of 5a exhibits a C–H–π bonded 2-D network.