Metal-organic polyhedra (MOPs) have emerged as novel porous platforms
for proton conduction, however, the concerted employment of both linker and
metal cluster vertex is rarely applied for the fabrication of MOPs-based high
conducting materials. Herein we report the synthesis of sulfonate-functionalized
polyoxovanadate-based MOPs for enhanced proton conduction
via the synergistic effect from linker and metal cluster node. MOPs
1 and
2 exhibit octahedral cage configuration constructed from {V
5O
9Cl}
vertex and 5-sulfoisophthalate linker. Owing to the ordered packing of
octahedral cages along three axes, 3D interpenetrated open channels that are
lined with high-density sulfonates are thus formed within
2. Coupled with the proton-conductive {V
5O
9Cl}
vertexs as well as protonated counterions, an extensive H-bonded network is
therefore generated for facile proton transfer.
2 exhibits high proton conductivity
of 3.02×10
-2 S cm
-1 at 65 °C under 90% RH, recording the
highest value for MOPs pellet sample. This value is enhanced ~1 order of
magnitude compared with that of carboxylate-functionalized analogue
3, clearly
illustrating the advantage of combining linker and metal cluster node for
enhanced proton conduction. This work will further promote the
exploitation of high proton conductive MOPs-based materials by the synergy
design strategy.