A new two-dimensional polyoxoniobate built by Lindqvist-type polyoxoanion and copper coordinated cations K2[Cu(H2O)6]{[Nb6O19][Cu(NH3)]2}·8H2O

A new two-dimensional (2D) polyoxoniobate K2[Cu(H2O)6]{[Nb6O19][Cu(NH3)]2}·8H2O (1) has been synthesized by the diffusion method and structurally characterized by elemental analyses, infrared (IR) spectrum, ultraviolet (UV) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) analysis and single crystal X-ray diffraction. Crystal structure analysis reveals that 1 exhibits a novel 2D network architecture constructed from Lindqvist-type [Nb6O19]8− polyoxoanions and copper coordinated cations. The XPS measurement indicates the oxidation state of Cu ion is +2. Surface photovoltage spectroscopy (SPS) and electric field induced surface photovoltage spectroscopy (EFISPS) measurements indicate that 1 possesses the n-type semiconductor characteristic.

► A new 2D polyoxoniobate has been synthesized by the diffusion method.
► 1 exhibits a novel 2D network architecture constructed from Lindqvist-type polyoxoanions and copper coordinated cations.
► The successful synthesis of 1 enriches the structural diversity of Nb-POMs.