Synthesis and Structure of Propionate-bridged Mixed-metal Cluster Compound: MoW_2O_2 (O_2CC_2H_5)_6 (H_2O)_3 ZnBr_4·4H_2O

The heterotrinuclear cluster compound [MoW_2O_2 (O_2CC_2H_5 )_6-( H_2O)_3] ZnBr4·4H_2O was prepared by the redox reaction of Mo (CO)_6 with Na_2W_O4 in propionic anhydride. The crystal is monoclinic of space group P2/c with a =16. 334(4) , b= 9. 657(5) , c=19. 889(9) ,β= 139. 79 (5)°,V= 2026 (2) ￣3 , Z=2 , D_c=2. 30 g/cm￣3 μ(MoKa) =106. 6 cm￣(-1) ,F(000)=1176 ,final R=0. 065 and R_ω=0. 072 for 1964 reflections with I≥3σ(I). In the structure of cation [MoW_2O_2 (O_2CC_2H_5 )_6 (H_2O)_3]￣(2+) molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.

Synthesis and Crystal Structure of Novel Mixed-metal Alkoxide Clusters of Ytterbium and Sodium: Yb_4O_4(O^iPr)_(16)Na_(12)

The mixed-metal cluster Yb4O4（OiPr）16Na12 has been synthesized and structurally determined by IR, elemental analysis, and single-crystal X-ray diffraction. The crystal belongs to the cubic system, space group P23 with a = b = c = 13.9788（3）A, V = 2731.55（10）A3, Z = 1, Dc = 1.202 g/cm3, Mr = 1977.42,/J = 3.480 mm-1, F（000） = 972, the final R = 0.0288 and wR = 0.1511 for 1677 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that Yb4O4（Oipr）16Na12 is centrosym- metric and the structure contains four ytterbium metals and twelve sodium metals, and each ytterbium atom is coordinated by six oxygen atoms. In addition, an ancillary computational analysis of the optimized molecular unit was provided. The large energy gap （3,31 eV） between HOMO and LUMO indicates that the structure framework is particularly stable.

A New Mixed-metal Monophosphate:Ba2Bi2Co(PO4)4

A new member of mixed-metal Ba2Bi2M-Ⅱ（PO4）4 monophosphate, namely Ba2Bi2Co（PO4）4, was synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction for the first time. It crystallizes in the orthorhombic system with space group Pnma（No. 62） and features a 3D architecture built up of adjacent zig-zag linear structures of [CoP4O（16）]∞ along [100], and further connected by [Bi2O（11）] dimers to form a 3D framework, where the Ba2＋ are located in the free space. The stereochemical activity of the Bi3＋ lone pair has also been discussed. The result of magnetic property measurement confirms the antiferromagnetic property of Ba2Bi2Co（PO4）4.

Unprecedented 1D Mixed-metal Polynuclear Cyclometalated Platinum Complexes： Synthesis, Structural Characterization and Spectroscopic Properties

The complexes [Pt2L2（μ-dppm）]（ClO4）2 （1） and {[Pt2L2（μ-dppm）Li（CH3CN）2]（ClO4）3}n （2）, where HL is 6-[4-（diethoxyphosphorylmethyl）phenyl]-2,2′-bipyridinyl and dppm is bis（diphenylphosphino）methane, have been synthesized and characterized. In complex 1 the platinum（Ⅱ） center adopts a distorted square planar coordination geometry. The polymer 2 exhibits a ＂stairstep＂ configuration with one-dimensional Pt（Ⅱ）N^N^CPO- Li（Ⅰ）-OPC^N^ NPt（Ⅱ） mixed-metal units which are linked through dppm. Both complexes have metal-metal interaction with Pt- Pt distances of 3.325（2） and 3.1432（9） A, respectively, and display strong metal-metal-to-ligand charge-transfer （MMLCT） triplet state emission. The density-functional-theory calculation was used to interpret the absorption spectra of the complexes.

Syntheses and Crystal Structure of [Cu(pyr)_3]·Hg_2I_6

A new compound containing discrete cationic and anionic complexes, [Cu(pyr)3]Hg2I6 (C30H24CuHg2I6N6), where pyr = 2,2-bipyridine, was prepared by the reaction of CuBr with pyr and HgI2 in a mixed solvent of acetone, methanol and acetonitrile. Single-crystal X-ray diffraction analysis indicates that it crystallizes in an orthorhombic system, Pna21 (No. 33), a = 33.1595(7), b = 9.4605(1), c = 13.0899(2) ? V = 4106.4(1) 3, Mr = 1694.67, Dc = 2.741 g/cm3, Z = 4, F(000) = 3012, m(MoKa) = 12.511 mm-1, R = 0.0736, wR = 0.1360 (I > 2(I)) and S = 1.218. The structure consists of discrete [Hg2I6]2- anions and [Cu(bipyridine)3]2+ cations. The double tetrahedral [Hg2I6]2- unit is formed by sharing one tetrahedral edge and possesses approximate D2h symmetry. The mononuclear Cu2+ ion is coordinated by six N atoms from three pyr molecules to form a slightly disordered octahedral geometry.

Syntheses, Crystal Structures and IR Spectra of Two Mixed Metal Complexes:〔Cr_nFe_(3-n)(μ_3-O)-(μ-O_2CC_2H_5)_6 Py_3〕Cl(n=1,2)

Two mixed metal complexes [Cr2Fe(μ3-O) (μ-O2CC2H5)6Py3]Cl (A)and [CrFe2 (μ3-O) (μ-O2CC2H5 )6Py3] Cl (B) have been prepared in non-aqueous sol-vents. Crystal (A) is monoclinic, space group C2/c, with a= 13. 782(3), b= 18. 381(4), c= 16. 643(2) A, β= 92. 84(5)°, V=4211. 1 (4) A3, Z=4, Mr= 887. 03, Dc= 1. 40 g/cm3, μ= 5. 0 cm-1, F(000) = 1836 and R(Rw) = 0. 057(0. 062) for 2134 unique reflections with I> 3δ(I). Crystal (B) is also monoclinic, space group C2/c ,with a= 13. 793(4), b= 18. 401 (6), c= 16. 657(5) A’, β= 93. 18(3)°, V=4221. 3(5) A3, Z= 4, Mr=890. 88, Dc= 1. 40 g/cm3, μ= 10. 5 cm-1, F(000) = 1844 and R(Rw) = 0. 067 (0. 069) for 2131 unique reflections with I>3δ(I). Both (A) and (B)have been characterized by IR spectra. Besides, the relations between the structuresand IR are discussed.

Synthesis and Characterization of the Molybdenum－Tungsten Mixed－metal Oxopolymetalate（Et4N）2［Mo4．5W1．5O19］

Molybdenum-tungsten mixed-metal oxopolymetalate(Et.N)2[Mo4.5W,1.5O19] has been synthesized and characterized by a complete X-ray crystallographic structure determination and a variety of physical measurements.The crystal is tetragonal,space group P4/mnc, with a= 10.771(5),c=14.245(4) A,V=1653(1 3 A 3,Dc=2.56 g/cm3,Z=2,Mr=1272.0,λ(MoKα)=0.71069 A,F(000)=1204,μ=70.04 cm-1,final R=0.043 and Rω=0.052 for 515 reflections with I】3σ(I).In the structure of[M6O19]2-(M6=Mo4.5)anion,six anion,six metal atoms form a regular octahedron with one oxygen atom situated in the center of the octahedron, twelve oxygen atoms disposed in M-O-M units and one terminal oxygen atom attached to each metal atom.The average distance of M-Ot is 1.71 A,while the M-(μ-O) being 1.909 A and M-(μ6-O) being 2. 314 A.The result of CV shows a reversible redox peak at -0.53 V and an irreversible reduced peak at -1.40 V.

Synthesis and Structure of Propionate－bridged Mixed－metal Cluster Compound：〔MoW2O2（O2CC2H5）6（H2O）3〕ZnBr4·4H2O

The heterotrinuclear cluster compound [MoW2O2 （O2CC2H5 ）6-（ H2O）3] ZnBr4·4H2O was prepared by the redox reaction of Mo （CO）6 with Na2WO4 in propionic anhydride. The crystal is monoclinic of space group P2/c with a =16. 334（4） , b= 9. 657（5） , c=19. 889（9） ,β= 139. 79 （5）°,V= 2026 （2） ￣3 , Z=2 , Dc=2. 30 g/cm￣3 μ（MoKa） =106. 6 cm￣（-1） ,F（000）=1176 ,final R=0. 065 and Rω=0. 072 for 1964 reflections with I≥3σ（I）. In the structure of cation [MoW2O2 （O2CC2H5 ）6 （H2O）3]￣（2+） molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.

W/Mo-polyoxometalate-derived electrocatalyst for high-efficiency nitrogen fixation

Ammonia is the feedstock chemical for most fertilizers and the alternative of renewable energy carriers.Environmentally benign electrochemical nitrogen reduction reaction (NRR) under mild conditions has been recognized as one of the most attractive strategies for N_(2) fixation.Herein,inspired by Mobased nitrogenase,W/Mo-doping electrocatalysts were developed with mixed-metal polyoxometalate H_(3)PW_6Mo_6O_(40) as the precursor for high performance electrocatalytic NRR.Trace amount of Pt was transplanted on the surface of W/Mo@rGO via in situ electroplating treatment to further improve the NRR performance.The resulting Pt-W/Mo@rGO-6 achieves excellent performance for NRR with a high NH_(3)yield of 79.2μg h^(-1)mg_(cat)^(-1) due to the multicomponent synergistic effect in the composite catalyst.The Pt-W/Mo@rGO-6 represents the first example of highly efficient NRR electraocatalyst derived from mixed-metal polyoxometalate,which exhibits outstanding stability confirmed by the constant catalytic performance over 24 h chronoamperometric test.This finding opens a new avenue to construct highly efficient NRR electrocatalyst by employing mixed metal polyoxometalate as the precursor under ambient conditions.

Bimetallic cobalt-nickel coordination polymer electrocatalysts for enhancing oxygen evolution reaction

Coordination polymers(CPs)have great potential to be used in electrocatalysis owing to their designable compositions and structures.It is highly challenging to apply CPs as electrocatalysts for oxygen evolution reaction(OER)on account of insufficient catalytic efficiency and relatively poor stability of current electrocatalysts.Herein,through a mixed-metal strategy,one-dimensional Co_(x)Ni_(1-x)-HIPA with dual active sites was synthesized and studied for OER electrocatalysts.By changing the metal ratio of CoxNi1-x-HIPA,the OER performance was well regulated.The optimized Co_(1/2)Ni_(1/2)-HIPA exhibited minimum reaction activation energy,and represented an overpotential of 367 m V to reach 10 mA/cm^(2) at 25℃.Moreover,an overpotential of 314 m V at 10 m A/cm^(2) was obtained from Co_(1/2)Ni_(1/2)-HIPA at 55℃.This mixed-metal strategy provides a feasible way for adjusting the electronic states of the electrocatalysts to improve the electrocatalytic OER performance.

Effect of Co(Ⅱ) dopant on the removal of Methylene Blue by a dense copper terephthalate

In this research, for the first time, a series of Co(Ⅱ) doped copper terephthalate(Co X-Cu BDC,where X is doping percentage) were successfully synthesized via solvothermal method and were tested for dye removal application. The physical properties of Co X-CuBDC were studied by several techniques including X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), energy-dispersive spectroscopy(EDS), thermogravimetric analysis(TGA)and Brunauer–Emmett–Teller(BET) surface area analysis. The incorporation of Co(Ⅱ) dopant leads to isomorphic substitution of Cu(II) in the CuBDC framework with the maximum doping percentage of 22. Doping and parent MOFs which are non-porous were used for removal of Methylene Blue(MB) from aqueous solution. Adsorption capacity of Co22-CuBDC and CuBDC are 52 and 58 mg/g, respectively, both of which are higher than the adsorption capacity recorded from several high porosity MOFs. Adsorption kinetic studies indicate that adsorption process follows pseudo-second order model while the adsorption mechanism is dominated by electrostatic attraction. Overall, even though these materials show non-porous characteristic,it can be used effectively in wastewater treatment application.