The phosphorescent and magnetic properties of a novel radical and its salt derived from 2,3′-biimidazo[1,2-a]pyridin-2′-one radical

Abstract

A novel neutral radical was synthesized from 2,3′-biimidazo[1,2-a]pyridin-2′-one radical via Cu(I) catalyzed ring-opening and carbon–carbon coupling reactions. The neutral radical (green-yellow phosphorescence) and its sulfate salt (blue phosphorescence) display obvious different phosphorescent colors, attributable to their different electronic structures, and stacking structures as demonstrated by powder X-ray diffraction patterns. The neutral radical itself exhibits weak antiferromagnetic property. The sulfate salt radical mainly presents diamagnetism between 58K and 380K owing to its dimeric structure, below 58K, it reveals complex magnetic behavior.