Ferrocene triphenylmethyl radical donor-acceptor compounds. Towards the development of multifunctional molecular switches

Abstract

Ferrocene-substituted polychlorinated triphenylmethyl radical (1) is a neutral paramagnetic donor-acceptor dyad that exhibits an intramolecular charge-transfer band in the near-infrared (NIR) region. It can be converted reversibly into its diamagnetic precursors 1- and 1H by chemical reduction and subsequent acid/base reaction or oxidized to the ferrocenium diradical 1+; each interconversion being accompanied with drastic changes of the optical properties. The new synthetic route described here allows the isolation of K+(18-Crown-6) [1]- salt in crystalline form, making possible the X-ray crystal structure determination. Because all derivatives exhibit extraordinary chemical and thermal stability, both in solution and in the solid state, radical 1 may be used as a model compound for the development of new multifunctional molecular switches. © ARKAT.