A New Class of Mixed Ionic-Electronic Conductor: Anthrone-lodine-Alkali Iodide Complexes

Abstract

Complexes of anthrone (A) with iodine (I) and alkali iodide (MI, M = Na, K, Rb, or Cs) have been prepared for the first time. These complexes (abbreviated AIMI) yield lustrous, rectangular crystals from acetone. At room temperature, the dc conductivity along the longitudinal direction of the entire series of the AIMI crystals decreases initially with time for about twenty minutes, but remains unchanged afterward. This indicates that the conduction is ionic as well as electronic in character. Their ac (1 kHz) conductivity, by contrast, is independent of time and is in the order of to lo-' Scm-I, varyingsystematically with the cation size in the following order: AICsI < AIRbI < AIKI < AINaI. It is concluded that AIMI complexes are a new class of mixed ionic and electronic conductor.