Ultrathin Anionic Tungstophosphite Molecular Wire with Tunable Hydrophilicity and Catalytic Activity for Selective Epoxidation in Organic Media

Directing the Linkage of Small Polyoxometalate Building Blocks Using (Benzene)ruthenium Cations

Oligomerization of monomeric molybdate and tungstate oxyanions in the presence of organometallic cations produces a group of organometallic-polyoxometalate clusters, which have diverse structures based on cubane-like {M4O4} units resembling the structure of oxide surfaces. This work investigated the oligomerization of [MoO4]2- and [WO4]2- oxyanions in aqueous solutions in the presence of {Ru(C6H6)}2+ as the organometallic structure-directing agents. The reactions produced a mixture of several species, and fractional crystallization by adjusting crystallization temperature and molar ratios of Ru:Mo or Ru:W allowed the isolation of seven types of (benzene)ruthenium-polyoxometalate complexes: [{Ru(C6H6)}4Mo4O16] (1), [{Ru(C6H6)(OH)}3HMoO4][MoO4] (2), [{Ru(C6H6)}4H2Mo5O20] (3), [{Ru(C6H6)}4W2O10] (4), Na6[{Ru(C6H6)}2H2W8O30] (5), [{Ru(C6H6)}5H2W6O24] (6), and [{Ru(C6H6)(OH)}6W2O7][{Ru(C6H6)}2{Ru(C6H6)(OH2)}2H2W8O30]2 (7). They comprise small, reactive iso-polyoxometalate building blocks that are capped by {Ru(C6H6)}2+ cations, resulting in cubane-like {Ru3MO4}, {Ru2M2O4}, or {RuM3O4} (M = Mo or W) structural motifs. Moreover, the molecular crystal of 1 contains extensive C-H···O hydrogen bonds, and it undergoes a reversible crystal-to-amorphous-to-crystal transition upon dehydration-hydration cycles.

A Zeolitic Octahedral Metal Oxide with Ultrahigh Porosity for High-temperature and High-humidity Alkyne/Alkene Separation

Zeolitic octahedral metal oxide is a newly synthesized all-inorganic zeolitic material and has been used for adsorption, separation, and catalysis. Herein, a new zeolitic octahedral metal oxide was synthesized and characterized. The porous framework was established through the assembly of [P2Mo13O50] clusters with PO4 linkers. Guest molecules occupied the framework, which could be removed through heat treatment, thereby opening the micropores. The pore characteristics were controlled by the cations within the micropore, enabling the adjustment of the interactions with alkynes and alkenes. This resulted in good separation performance of ethylene/acetylene and propylene/propyne even under high temperature and humidity conditions. The high stability of the material enabled the efficient recovery and reuse without discernible loss in the separation performance. Due to the relatively weak interaction between the adsorbed alkyne and the framework, the adsorbent facilitated the recovery of a highly pure alkyne. This feature enhances the practical applicability of the material in various industrial processes.

Vanadium-Enhanced Intramolecular Redox Property of a Transition-Metal Oxide Molecular Wire

Transition-metal oxide molecular wires are inorganic 1D polymers with elemental diversity. The properties of the materials are tuned by tuning the chemical compositions. The phosphovanadomolybdate molecular wire is synthesized, which is an isostructural material of the phosphomolybdate molecular wire. V is randomly located in the crystal to form {[(HP^IIIO₃)(Mo^VI₅O₁₅)(V^VO₃)]^3-}_n, which is incorporated into the material after the formation of the phosphomolybdate molecular wire. The heat-triggered redox reaction via the intramolecular electron-transfer and oxygen-transfer procedure is promoted after V substitution. Oxygen transfers from {V^VO₆} to {HP^IIIO₃}, and an electron transfers from {HP^IIIO₃} to {V^VO₆} with oxidation of the triangle {HP^IIIO₃} to the corner-sharing tetrahedral {P^V₂O₇} and reduction of the octahedral {V^VO₆} to the pyramidal {V^IVO₅}. The material shows catalytic activity for the aerobic oxidation of alcohol to aldehyde, and good activity with high selectivity is obtained.

Zeolitic Vanadomolybdates as High-Performance Cathode-Active Materials for Sodium-Ion Batteries

Developing new cathode-active materials for rechargeable batteries is important to fulfill the growing demands of energy transformation, storage, and utilization. Zeolitic transition-metal oxides based on vanadomolybdate, constructed by pentagon metal-oxygen clusters as building blocks and metal ions as linkers in a trigonal symmetry, are good candidates for cathodes of Na rechargeable batteries. The material is activated via amorphization of the crystal structure in the ab plane during discharging process, keeping the molecular structure of the building blocks stable, which causes high specific capacity and good cycle performance.

Tin oxide-coated transition metal oxide molecular wires for biomass conversion

Herein, acid catalysts were prepared by coating Sn oxide on molecular wires for the production of levulinic acid from cellulose.

Synthesis of a superparamagnetic ultrathin FeCO3 nanorods–enzyme bionanohybrid as a novel heterogeneous catalyst

A novel superparamagnetic ultrathin FeCO₃ nanorods–enzyme bionanohybrid heterogeneous catalyst has been developed.