Synthesis and Crystal Structure of LanthanideHetero-polymolybdate Complex:(NH_4)_(12)H_(10)〔Nd_4Mo_(29)O_(104)(H_2O)_(12)〕·22H_2O

11NTRODUCTIoNNowadaysheteropoly-complexesaremorenoticeableespeciallyinthefieldofcat-alystbecauseinsomeorganicsynthesestheycanbeusedasanoxidativetypeoracidictypecatalystorasboth.Ontheotherhandtherearemanytheoreticaltopicsaboutheteropolycomplexinwhichmanyscientistsareinterested.Inthefieldofpolyacidchemistrythesynthesisofanewheteropolycomplexisanimportantaspect.Molybdenumcanformbinaryheteropolymolybdatecomplexcompoundswithmanymetalandnon-metalelements.Indifferentcompoundstheratioofheteroatoms…     

Synthesis and Crystal Structure of [(NH_4)_6][Gd_2Mo_(36)O_(112)(H_2O)_(20)]·52H_2O

1 INTRODUCTION There is considerable interest in the heteropolymetalates in view of their potential applications in many fields, such as, catalysis, biology, medicine, magnetochemistry, and materials science[1～5]. It has been well- known that the rare earth elements are highly oxophilic and the anion of polyoxomolybdates have oxygen-rich composition, which can be used as synthons for the construction of novel heteropolymetalates. Since the structure of polyoxoanion 36-molybdate Mo36O1128…     

Synthesis and Crystal Structure of Lanthanide Heteropolymolybdate Complex (NH_4)_(11)Gd[Gd_4Mo_(29)O_(100)(H_2O)_(23)]· 25.75H_2O

The title complex crystallizes in the triclinic system, space group P1with a = 16.9568(5), b = 18.8631(6), c =24. 1640(8) (A。), α = 100. 110(1), β=92.330(1), γ=113.368(1)°, V=7602.54(4) (A。)3, Dc =3.002 g/crn3, F(000) =5893, Mr=6245.25, μ(MoKα)=5.010mm-1, Z=2andfinalR=0.0722and wR = 0. 1960 for 16015 observed reflections with Ⅰ≥2σ(Ⅰ). The Gd( Ⅲ ) ion is coordinated by nine oxygen atoms, forming a distorted mono-capped square antiprism, while the Mo( Ⅵ ) ions have their different coordination numbers such as 4, 5 and 6 with different configurations such as tetrahedron, squar e pyramid and octahedron, respectively.     

Synthesis and Crystal Structure of Neodymium Heteropolymolybdate Complex Na_4(NH_4)_(10)[Nd_4 Mo_(29)O_(100)(H_2O)_(16)]·34H_2O

1INTRODUCT1ONThestudyofheteropolycomplexeshasbeenstartedmorethanonehundredyearsago.lnthepasttwentyyearstheheteropoly-coinplexesoftungstenandmolyb-denumhavebeenusedinpreparingcatalystfield,biologicalandionexchangemateri-als.Sothesecomplexeshavebeendeeplystudiedandexaminedbynewtechnicalmethodst2~7J.Wehavereportedthesynthesismethodandcrystalstructureoflanthanideele-mentneodymiumheteropolymolybdate(NH4),2H,,tNd'Mo,,O,,,(H,O)1,j.22H,O('i.Inthispaperwereportthesynthesismethodandcrystalstruc…     

Hydrothermal Assembly and Structural Characterization of an Octamolybdate Supported Copper(Ⅰ) Tetramer:[Cu2(1,10-phen)2(4,4'-bpy)]2[Mo8O26]·4H2O

A hydrothermal reaction of copper acetate with ammonium molybdate, 4,4'-bpy (4,4'-bipyridine) and 1,10-phen (1,10-phenanthroline) led to the formation of brown crystals of [Cu2(1,10-phen)2(4,4'-bpy)]2 [Mo8O26]@4H2O 1. Single-crystal X-ray analysis has revealed that 1 C68H56N12O30Cu4Mo8 crystallizes in the triclinic system, space group P ī with a = 11.270(3), b = 13.113(6), c = 13.906(3)A, α = 103.33(4),α = 98.54(2),β= 101.29(2)°, V = 1920.1(1)A3, Mr = 2542.9(3), Z = 1, Dc = 2.199 g/cm3, μ= 2.435 mm-1, F(000)= 1240, the final R = 0.0445, wR = 0.1082 and S = 1.021 for 5052 observed reflections with I>σ2(I).It consists of copper Ⅰ tetramer units and α-[Mo8O26]4- anions, which are further attached into a three-dimensional framework through hydrogen bonding and π-π stacking interactions.     

Hydrothermal Assembly and Structural Characterization of an Octamolybdate Supported Copper (Ⅰ) Tetramer: [Cu_2(1,10-phen)_2(4,4′-bpy)]_2[Mo_8O_(26)]·4H_2O

1 INTRODUCTION The recent expansion of the field of heteropolyoxometalate chemistry derives from their vast topological structures and applicable physical properties[1～5]. One of the crucial strategies for the molecular design of solid materials is how to apply hydrothermal synthesis method to introduce some interesting transition metal coordinated fragments into the covalent backbones of solid materials. Studies have been focused on organic-inorganic hybrid materials containing one kin…     

机械化学法制备的Al/Ce复合氧化物负载NiMo催化剂的加氢脱硫活性(英文)

将Al和/或Ce的硝酸盐与NH_4HCO_3球磨混合,采用机械化学法制备了Al_2O_3-CeO_2载体(其中Ce含量为1-10 wt%),再以杂多钼酸盐(NH_4)_4NiMo_6O_(24)为活性金属Ni和Mo的前驱体,通过浸渍法制备NiMo_6/Al_2O_3-CeO_2催化剂,并将其用于1-苯并噻吩(BT)的加氢脱硫(HDS)反应中.运用化学分析、X射线衍射、N_2吸附-脱附法、H_2程序升温还原、NH_3程序升温脱附和X射线光电子能谱对催化剂的物化性质进行了表征.结果表明,催化剂的酸性随着载体中Ce含量的增加而下降.Ce修饰的Al_2O_3载体表面的NiS/MoS原子比下降了2倍.NiMo_6/Al_2O_3催化剂表现出最高的HDS活性(以单位重量催化剂计),其酸性和表面MoO_xS_y物种的浓度(Mo~(5+)浓度)也最高;当催化剂中Ce含量逐渐增加到10 wt%以上时,其活性逐渐将为0.与浸渍法制得的参比催化剂相比,前驱体和催化剂组成相同的情况下,采用机械化学法制得的所有催化剂活性明显提高.