Electrochemical synthesis of decavanadates-containing inorganic complex and inorganic-organic hybrid in aqueous solutions

Abstract

Polyoxometalate (POM) can serve as functional inorganic nucleophilic polydentate ligands to incorporate 3dmetal or 4f-metal ions to manufacture novel 3d-metal substituted POM materials or 4f-metal substituted POM materials with potential applications. Two polyoxovanadate-containing compounds with decavanadate anions, Cs4[Cu(OH)(H2O)3]8(H6V6IVV4VO28)(V10VO28) (1) and K2[Cu(H2O)(C6H15NO3)]2(V10O28)∙2H2O (2), have been electrochemically synthesized in aqueous solution. Electrochemical driving force was utilized to perform the crystal growth of the title decavanadate-containing inorganic transition-metal complexes (TMCs) and inorganic–organic hybrid compound. The technique is novel and noteworthy because it allows for the synthesis of complexes based on thermally unstable POM anions that cannot be synthesized by conventional hydrothermal methods while maintaining the plenary POM structure under mild synthetic conditions. Furthermore, the adaption of the technique allows the incorporation of a triethanolamine-copper complex as a second building unit (SBU) for the exploration of inorganic-organic hybrid via electrochemical methods. Interestingly, the title compounds cannot be obtained via conventional evaporation methods either, emphasizing the unique nature of the synthetic method due to electroreduction.