Photochromic Polyoxoniobates with Photoinduced "D-f-A" Electron Transfer Mechanism.

Compounds with redox activities have appealing applications in catalytic, electronic and magnetic properties, but the redox inert of polyoxoniobates (PONbs) significantly limits their applications for a long time. In this work, we are able to integrate organophosphate and lanthanide cluster into PONb to create the first family of inorganic-organic hybrid organophosphate-Ln-PONb composite clusters. These novel species not only present the first family of redox active PONbs that can be reduced to form long-lived "heteropoly blues" under ambient conditions, but also a new photochromic system. More importantly, the analyses of the electronic configurations and photochromic properties for a series of designed proof-of-concept PONbs models allow us to discover a D-f-A electron transfer mechanism, that is, photoinduced electron is transferred from a photosensitive organophosphate electron donor (D) to the NbV electron acceptor (A) through the unoccupied 4 f-orbitals of Ln (f). This work paves the way for developing diverse PONb-based redox materials and expanding the possibility of the applications of PONbs in the redox chemistry.

A Three-Dimensional (3D) Indium-Containing Polyoxoniobate Framework Based on {In5Nb71}n Helical Pillars.

A rare 3D Indium-containing polyoxoniobate framework {H9[Cu(en)2(H2O)2][Cu(en)2]12[In(en)]5[Nb23-O65(OH)3(H2O)2]{Nb24O67(OH)2(H2O)3]2}·68H2O(1), based on the In-containing polyoxoniobate cluster, {[In(en)]5[Nb23O65(OH)3(H2O)2][Nb24O67(OH)2(H2O)3]2}35- ({In5Nb71}) and [Cu(en)2]2+ linkers has been successfully synthesized. The nest-like cluster {In5Nb71} is constructed from one brand-new V-shaped {Nb23O70}, two triangle-shaped {Nb24O72} and five [In(en)]3+. The [In(en)] fragments link {Nb24O72} and {Nb23O70} units into unique {In5Nb71}n helical pillars. The copper-amine complexes connect the {In5Nb71}n helical pillars into a three-dimensional (3D) inorganic-organic hybrid In-Cu-containing framework. This material also exhibits good ionic conductivity and vapor adsorption capacity properties.

An organophosphate 3d-4f heterometallic polyoxoniobate nanowire.

Four different structural compositions of organophosphate, 3d transition metal, 4f lanthanide and polyoxoniobate (PONb) are unified in a system for the first time to form a new type of organophosphate 3d-4f heterometallic inorganic-organic hybrid PONb nanowire. Interesting magnetic anisotropy and slow magnetic relaxation are found in the PONb nanowire.

3d-4f Heterometallic cluster incorporated polyoxoniobates with magnetic properties.

A series of 3d-4f heterometallic cluster incorporated polyoxoniobates (PONbs) with different magnetic properties were first made and characterized. This work not only provides a promising strategy to make new heterometallic cluster incorporated PONbs but also demonstrates an ideal model to probe how transition-metal ions influence the magnetic property of PONbs.

Proton conductive polyoxoniobate frameworks constructed from nanoscale {Nb68O200} cages.

Nanoscale {Nb68O200} cages have been successfully employed as flexible and stable secondary building units to combine with bridging copper-amine complexes to construct two proton conductive polyoxoniobate frameworks, demonstrating a promising strategy for making new porous materials.