Синтез гетеро-дирадикалов с помощью реакции Соногашира

Abstract

Iodine- and ethynyl-containing verdazyls, and nitronyl nitroxides were investigated as building blocks for the synthesis of multi-spin systems via the Sonogashira coupling. The reactivity of the building blocks indicates that oxoverdazyl iodides are effective starting components for the synthesis of diradicals via the Sonogashira reaction. The described method allows combining different spin moieties, thereby simplifying the design of tolane-bridged diradicals and screening of their properties. The novel obtained compounds were characterized by cyclic voltammetry (CVA), UV-Vis and electron spin resonance (ESR) spectroscopies. Although the electrochemical investigation and electronic spectra showed a negligible influence of radical moieties on each other, ESR data revealed a strong exchange interaction between two unpaired electrons.