Two Unprecedented Germanoniobate Frameworks Based on High-Nuclearity Peanut-Shaped {Ge 12 Nb 38 } Clusters.

By variation of the amount of GeO 2 , two organic-inorganic hybrid germanoniobate frameworks with 6-connected pcu and 10-connected bct topologies were constructed from peanut-shaped {α-Ge 12 Nb 38 } and {β-Ge 12 Nb 38 } clusters, respectively. The {α-Ge 12 Nb 38 } and {β-Ge 12 Nb 38 } clusters contain the most Ge centers of germanoniobates reported so far. The compounds exhibit proton conduction properties with a conductivity of 3.04 × 10 -4 S·cm -3 for 1 and 1.62 × 10 -4 S·cm -3 for 2 at 85 °C and 98% RH. The water vapor adsorption capacities for 1 and 2 are 5.86 and 4.40 mmol·g -1 , respectively.