Photoluminescence and Magnetism Study of Blue Light Emitting the Oxygen-Bridged Open-Cubane Cobalt(II) Cluster

Abstract

A new cubane-based cobalt(II) cluster, [Co4L4] (1), where H2L = 2-((E)-(2-hydroxyethylimino) methyl)-4-chlorophenol has been prepared using a solvothermal process and characterized by structural, optical and magnetism. The crystal structure of 1 consists of a tetranuclear Co4O4 core in an open-cubane framework. Each cobalt(II) ion is penta-coordinated in a distorted square pyramidal geometry (tau(Co1=Co1i) = 0.030, tau(Co2=Co2i) = 0.023). Furthermore, the photoluminescence analysis indicates that 1 has a strong blue emission which should be attributed to coordination of the metal to the ligand. The temperature dependence of the magnetic susceptibilities of 1 shows antiferromagnetic coupling (J= - 26.61 +/- 0.01) between cobalt(II) ions.