Niu, Jingyang | Search NASA

DOE OSTI2020

A large molecular cluster with high proton release capacity

We present a single molecular polyoxometalate cluster (K-41[(P2W12Nb6O62)(6){Mn-3(OH)(3)(H2O)(6)}(4){Mn3Na(H2O)(16)}]center dot 26H(2)O) with controllable release of a large number of protons (similar to 40 per molecule) in its aqueous solution upon addition of a base. The deprotonation/protonation process is reversible with the clusters remaining intact. This molecule can also absorb up to 11 protons per cluster when an acid, HCl, was added to its original aqueous solution. To the best of our knowledge, such large proton absorption/release capacity along with excellent stability is unprecedented.

Zhang, Dongdi↗

DOE OSTI2020

Unraveling the Effects of Cobalt on Crystal Growth and Solution Behavior of Nb 6 P 2 W 12 -based Dimeric Clusters

We report the synthesis, characterization, and solution self-assembly of plenary Nb 6 P 2 W 12 -based transition-metal substituted polyoxometalate, which is obtained by simply adding transition metals (Co 2+ ) into aqueous solution containing cluster [(NbO 2 ) 6 P 2 W 12 O 56 ] 12- , which is obtained by an in situ synthetic method. The incorporation of Co 2+ ions significantly affects the crystal structure, resulting in the formation of a 1D chain-like crystal and the first example of a niobotungstate-based cobalt derivative cluster. The behavior and stability of this cluster in solution are confirmed by time-resolved static light scattering, dynamic light scattering, small-angle X-ray scattering, and electrospray mass spectrometry studies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗