Assembly of Four Ternary Polyoxometalate Aggregates by Integrating Presynthesized {XWNbO} (X = Si/Ge) Units Using Molybdenum-Oxo Clusters.

Polyoxometalates (POMs) have good potential for applications in different fields, including conducting materials, optics, and electrocatalysis. Of particular significance is the synthesis and development of addendum POMs. Molybdenum-oxo clusters, which are renowned for their diverse structures and electronic properties, were utilized to facilitate the synthesis of innovative materials. Herein, we employed presynthesized {XW NbO} (X= Si/Ge) polyanions as secondary building units and different molybdenum-oxo clusters as linkers. Four new addendum POMs were constructed, including two dimeric compounds Cs[H(SiWNbO)(MoOCO)]·19HO () and Cs[H(GeWNbO)(MoOCO)]·17HO (), and two tetrameric compounds Cs(NH)[(SiWNbO)(MoO)]·42HO () and CsK[H(GeWNbO)(MoO)]·39HO (). Notably, this is the first report of Mo/W/Nb ternary mixed-addendum POMs. In addition, compounds and facilitate the transfer of protons through extended hydrogen-bonding networks with conductivity values of 1.16 × 10 and 7.73 × 10 S·cm at 85 °C and 98% relative humidity, respectively. Furthermore, no discernible decline in conductivity was noted over the course of 10 h.