A Copper(I)-Thioarsenate(III) Inorganic Framework Directed by [Ni(en)3]2

New types of open-framework vanadium borophosphates with photocatalytic properties

The exploration of new open-framework polyoxometalates is very significant in structural chemistry and materials science. Herein, three new organic hybrid three-dimensional vanadium borophosphates (H3O)7(H2aeae)3{[Cd(H2O)3]2[H3O⊃(V2BP2O12)6]}·15H2O (1, aeae = 2-(2-aminoethylamino)ethanol) and (H3O)5(H2aeae)3{[TM(H2O)2.5(H2aeae)0.5]2[H3O⊃ (V2BP2O12)6]}·9H2O [TM = Mn(2), Co(3)] were hydrothermally prepared and structurally characterized. The three vanadium borophosphates contain similar 12-member ring crown-shaped clusters [(V2BP2O12)6]18- based on the linkage of six [V2O8] dimers and six [BP2O10] units. The [(V2BP2O12)6]18- cluster is further bridged by the unsaturated [Cd(H2O)3]2+ or [TM(H2O)2.5(H2aeae)0.5]3+ complexes to build new types of open-framework vanadium borophosphates with pores and cavities retained by the protonated H2aeae2+, H3O+ and free H2O. Surprisingly, the monodentate H2aeae2+ ligand coordinating with a metal center was observed in 2 and 3 for the first time as the aeae molecule acted as the trichelating ligand. Their optical absorption edges were determined to be in the range of 2.61-2.68 eV using solid-state UV-vis spectroscopy. 1-3 exhibited excellent photocatalytic activity towards methylene blue (MB) degradation under visible light irradiation, which presented the first example of organic hybrid open-framework vanadium borophosphates as the photo-catalysts for MB degradation.

Two Electrocatalytic Selenoarsenates with Manganese Complex Cations as Counterions

The discovery of new organic hybrid chalcogenidometalates is of great importance for structural chemistry and functional material. Here, new types of organic hybrid selenoarsenates [Mn(dien)2]2[AsII4Se6] (1, dien = diethylenetriamine) and [Mn(dien)2]2[Mn(AsIIISe3)2] (2) have been solvothermally synthesized by the reaction of K3AsO3, Se, and MnCl2·xH2O (x = 0, 2) in dien solution at 120 °C. 1 presents a hitherto unknown [AsII4Se6]4- anion with low-valent As2+ ion, which comprises a centrosymmetric six-membered [AsII4Se2] ring in chair-like conformation, while 2 contains a new type of heterometallic selenoarsenate(III) [Mn(AsIIISe3)2]4- constructed by the connection of one tetrahedral [MnSe4] and two rare noncondensed [AsIIISe3]3- anions. 1 and 2 were first combined with nickel nanoparticle (Ni) and the nickel foam (NF) for fabricating the 1/Ni/NF and 2/Ni/NF electrodes, which exhibited excellent oxygen evolution reaction electrocatalytic property with a low overpotential of 248 mV for 1 and 219 mV for 2 at 10 mA cm-2 in alkaline media.

Strong Photocurrent Response of Selenoarsenates With Different Transition Metal Complexes as Structure-Directing Agents

Four selenoarsenates with different transition-metal complexes [Co(tren)₂H]AsSe₄ [tren = tris(2-aminoethyl)amine] (1); [Ni₂(dien)₄](As₂Se₅) (dien = diethylenetriamine) (2); [Zn(tren)]₂(As₂Se₅) (3) and [Mn(tren)]₂(As₂Se₅) (4) were solvothermally synthesized in a mixed solvent of organic amine and alcohol solution. The compounds 1-4 have pyramidal/tetrahedral structures (AsSe₃/AsSe₄), and contain transition metal (Co²⁺, Ni²⁺, Zn²⁺ and Mn²⁺) complex that form distinct zero-dimensional (0-D) clusters. Arsenic atoms form a tetrahedron in compounds 1 and 2; 1 consists of discrete tetrahedral (AsSe₄) and transition metal complex [Co(tren)₂]²⁺; 2 is composed of an anion [As₂Se₅]^4- cluster and transition metal complex [Ni(dien)₂]²⁺. In compounds 3 and 4, arsenic atom forms a pyramidal AsSe₃ and the two pyramidal AsSe₃ share a corner connection to form a dimer [As₂Se₅]^4-; 3 is characterized as a cluster consisting of two unsaturated [Zn(tren)]²⁺ caiton linked by a dimer (As₂Se₅)^4- linkage; in 4, unsaturated [Mn(tren)]²⁺ caiton is linked to two trigonal-bipyramidal [Mn(tren)]Se via dimer (As₂Se₅)^4- to form [Mn(tren)]₄[As₄Se₁₀] cluster. To our knowledge, [Zn(tren)]₂(As₂Se₅) (3) is the first zinc selenoarsenate containing the (As₂Se₅)^4- anion type. Furthermore, the Mn²⁺ ions adopt a trigonal-biyramidal (five-coordinate) and octahedral (six-coordinate) environment. Adding K₂CO₃/Cs₂CO₃ to the synthesis system is necessary and may act as a mineralizer. Several properties of compounds 1-4 have been characterized in our studies, in particular their strong photocurrent response characteristics under visible light irradiation.

The rare example of hybrid chalcogenoarsenates(III) incorporating trivalent vanadium complexes

A series of new hybrid vanadium chalcogenoarsenates(III) [VIII(en)2AsIIIS3] (1, en = ethylenediamine), [VIII(dap)2AsIIISe3] (2, dap = 1,2-diaminopropane), [VIII(teta)AsIIIQ3] {Q = S (3), Se (4), teta = triethylene-tetramine}, and [VIII2(en)6(μ2-O)][As2Se5] (5)...

Two Organic Hybrid Manganese Selenoarsenates: The Discovery of One-Dimensional Low-Valent Selenoarsenate(II)

Two organic hybrid manganese selenoarsenates, [Mn(en)₃][MnAs^II₂Se₄] (1; en = ethanediamine) and {[Mn(atep)]₂[Mn(tepa)](As^VSe₄)₂} [2; atep = 4-(2-aminoethyl)triethylenetetramine], were made under mild solvothermal conditions. 1 is a new type of one-dimensional low-valent selenoarsenate(II) constructed by the linkages of tetrahedral [MnSe₄] units and two manners of bridging of [As^II₂Se₄]^4- anions. 2 comprises a neutral {[Mn(atep)]₂[Mn(tepa)](As^VSe₄)₂} molecule with a rare seven-coordinated manganese center, which represents the sole example of an organic hybrid selenoarsenate with the [Mn(tepa)]²⁺ complex as the bridging group. Both 1 and 2 exhibit special photocurrent responses upon visible-light illumination and magnetic properties.