Different types of polyoxometalate-directed diverse architectures derived from the rigid ligand pyrazine-bis(triazole): assembly, electrocatalysis, and dye adsorption

Abstract

Three new polyoxometalate (POM)-based metal–organic complexes, {Ni3(Hpytty)2[AlMo6(OH)5O19](H2O)4(CH3O)}·5H2O (1), {Ni3(Hpytty)2 [CrMo6(OH)5O19](H2O)10}·6H2O (2), and {Co2(pytty)[γ-Mo8O26]0.5 (H2O)5}·4H2O (3) (H2pytty = 3-(pyrazine-2-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl), have been prepared by the solvothermal method. Complexes 1 and 2 show similar 0-D structures containing a [Ni3(Hpytty)2]4+ and Anderson-type [AlMo6(OH)5O19]4− /[CrMo6(OH)5O19]4− anions. The [γ-Mo8O26]4− anion was generated in-situ from the [IMo6O24]5− anion in 3, which shows a 3-D coordination structure constructed from 2-D Co-pytty metal–organic layers and γ-Mo8 anions. The results reveal that the POMs play key roles in tuning the diverse architectures of the final complexes. For 1–3, their adsorption properties for MB/GV and their electrochemical activities have been investigated.