Layered V–B–O polyoxometalate nets linked by diethylenetriamine complexes with dangling amine groups

Abstract

Two layered V–B–O contained polyoxometalate (POM) net structures, denoted as SUT-12 and SUT-13, are reported here. SUT-12 was synthesized by the boric acid flux method, and it represents the first 2D structure constructed from the V₆B₂₀ vanadoborate cluster. SUT-13 was synthesized by the hydrothermal method and constructed from V₁₂B₆P₁₂ vanadium borophosphate clusters. In both structures, the vanadoborate or vanadium borophosphate clusters were linked through in situ formed Zn(DETA)₂ or Cu(DETA)₂ complexes. Surprisingly, for all DETA molecules in the two metal complexes, there is one dangling amine group when it is coordinated to the metal. The phenomenon of the dangling amine group feature is abnormal and the Cu(DETA)₂ complexes in SUT-13 were taken as an example and studied by the density functional theory (DFT) calculations in order to understand this unusual feature.