A cobalt(II) complex based on imidazole dicarboxylate ligand with high proton conductivity

In order to search for new crystalline proton conductive materials, a highly stable Co(II) complex, namely, [Co (HPhIDC)(4,4' -bipy)] (1) (H3PhIDC = 2-phenyl-4,5-imidazole dicarboxylic acid, 4,4' -bipy = 4,4'-bipyridine) has been successfully synthesized under hydrothermal conditions and structurally characterized. 1 exhibits high thermal, water and chemical stabilities, which promoted us to investigate its proton conductivity in water vapor. The results showed that proton conductivity of 1 was dependent on temperature and relative humidity (RH). The optimal proton conductivity of 1 reaches up to a highest value of 1.35 x 10(-4) S center dot cm(-1) at 373 K under 98% RH. According to the E-a value, the proton conduction mechanism of 1 maybe a combination of Grotthuss and Vehicle mechanisms at 98% RH and major Vehicle mechanism at 75% RH.

Automated summary

A highly stable Co(II) complex was synthesized and its proton conductivity in water vapor was investigated. The results showed that the proton conductivity was dependent on temperature and relative humidity. Under high humidity conditions, the complex exhibited good proton conductivity.