The title compound, {(H3O)4(NH4)4[Mo8O28]?2H2O}n 1, has been synthesized from the reaction of Zn(OAc)2 and (NH4)6Mo7O24?4H2O in aqueous solution at ambient tempe- rature, and its crystal structure was determined by X-ray single-crystal analysis with the following crystallographic data: monoclinic system, space group P21/n, a = 9.5234(6), b = 11.3235(8), c = 14.8812(10) ?, β = 107.467(2)o, V = 1530.77(18) ?3, Z = 4, F(000) = 1336, μ = 3.293 mm-1 and Dc = 3.037 g/cm3. The final R = 0.0619 for 2691 observed reflections (I > 2σ(I)). X-ray crys- tal structure analysis showed that the novel one-dimensional chain compound is built up by basic {Mo8O28} units via single μ2-O, and such chains are further linked into a three-dimensional net- work by hydrogen bonds.
The title compound, [Zn(NDC)(2,2′-bipy)]n (NDC = 1,5-naphthalenedicarboxylate, 2,2′- bipy = 2,2′-bipyridine), has been synthesized by a hydrothermal reaction and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 19.967(4), b = 17.158(3), c = 14.276(3) ’, β = 129.623(5)°, V = 3767.4(12) ’3, Z = 8, C22H14N2O4Zn, Mr = 435.72, Dc = 1.536 g/cm3, F(000) = 1776, μ(MoKa) = 1.336 mm-1, the final R = 0.0777 and wR = 0.2447 for 2032 observed reflections (I > 2σ(I)). The Zn(II) ion is six-coordinated by two nitrogen and four oxygen atoms in a distorted octahedral environment. NDC ligand has a bis(bridging bidentate) coordination mode in the compound. The zinc atoms are linked by carboxylate groups of NDC ligand in bridging mode into a one-dimensional zigzag chain.
MENG Ze-Rong HE Xiang WU Xiao-Yuan CHEN Li-Juan YANG Wen-Bin LU Can-Zhong
A novel transition-metal ion coordination-linked network compound {Na4[Co- (H2O)2(NH2NH2)2Mo8O27]?16H2O}n 1 was synthesized by the reduction reaction of Na2MoO4? 2H2O, NH2NH2?2HCl and Co(OAc)2?4H2O in aqueous solution at ambient temperature and structurally characterized. Crystal data for 1: triclinic system, space group P1, a = 9.5544(2), b = 9.8640(2), c = 11.6338(3) ?, α = 103.3790(10), β = 100.5600(10), γ = 96.2750(10)o, V = 1035.32(4) ?3, Z = 1, Dc = 2.789 g/cm3 and R = 0.0453. The X-ray crystal structure analysis shows that 1 is constructed by octamolybdate anions linked via corner-sharing interactions and hetero-metal links into the polymeric anionic sheet [Co(H2O)2(NH2NH2)2Mo8O27]n 4n-, and further allied by [Na4(H2O)12]n 4n+ sodium chains into a 3D framework with z-shaped channels. The mag- netic study of compound 1 indicates that weak antiferromagnetic coupling interaction occurs be- tween the cobalt centers.
A mixed-valent hexanuclear complex [CuIICuI2(pbi)2Br2]2 (pbi = (2-(2-pyridyl)-ben- zimidazole) exhibiting a dimeric unit bridged by two Br atoms was synthesized by hydrothermal reaction. Interestingly, there exist intramolecular and intermolecular π-π stacking interactions as well as metal- aromatic ring interactions in the title complex. The crystal belongs to the monoclinic system, space group P1, with a = 7.1061(9), b = 12.1008(13), c = 14.0711(17)A, α = 91.742(8), β = 100.155(9), γ = 90.486(7)o, V = 1190.3(2) ·3, Z = 2, C48H32Br4Cu6N12, Mr = 1477.74, Dc = 2.061 g/cm3, F(000) = 718, μ(MoKα) = 6.039 mm-1, the final R = 0.0481 and wR = 0.0974 for 3426 observed reflections (I > 2σ(I)).
The pure phases of alkaline earth molybdates MMoO 4, where M=Mg, Ca, Sr or Ba, were synthesized via the calcination of the related citrato oxomolybdate complexes. The mixed metal oxides can be highly dispersed at the atomic level due to the existence of uniform citrato oxomolybdenum precursors in definite composition. The complexing effect helps to produce the fine-grained oxides with particle size in the ultrafine scale（<100 nm） at heat-treatment temperatures below 500 ℃. The structures of the precursor complexes and the finally heat-treated particles were studied by means of IR, XRD, DSC, DTA and TG techniques. The morphologies of the particles were observed by using the SEM technique. The average particle sizes were calculated to be in the range of 3050 nm based on X-ray diffraction line-broadening and SEM images, indicating the poor conglomeration of crystallite at low temperatures.
The Mg,Al,Alkaline-earth mixed oxides were synthesized by co-precipitation of two mixed solutions and then loaded with Ru to get the Ru-based catalyst.X-ray diffraction,CO2-adsorption,N2 physical-adsorption and SEM were introduced to characterize the phase,basicity,area,and configuration of the surface of the mixed oxide.The ammonia synthesis experiment was carried out under the fluxin of 3H2/1N2,with the velocity 2100 mL/h and pressure 0.2 MPa.The activity test shows that the catalyst supported on mixed oxide has far more better activity than those supported on single oxide.It can be concluded from the result of the characterization and activity test that the activity of the catalyst was mainly affected by the basicity of the surface rather than the surface areas.
