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

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 with a = 11.270(3), b = 13.113(6), c = 13.906(3) ? = 103.33(4), b = 98.54(2), g = 101.29(2)? V = 1920.1(1) ?3, Mr = 2542.93, Z = 1, Dc = 2.199 g/cm3, m = 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 >2s(I). It consists of copper (Ⅰ) tetramer units and -[Mo8O26]4- anions, which are further attached into a three-dimensional framework through hydrogen bonding and - stacking interactions.

Unprecedented α-Octamolybdate Derivative Containing Hexad-track Cu―bpe Chains,2{[Cu(bpe)]_6[α-Mo_8O_(26)]_(3/2)}·[Cu(bpe)]_3·3H_2O

A new inorganic-organic hybrid constructed from α-octamolybdate polyoxometalates modified by hexad- track Cu―bpe chains, 2{[Cu（bpe）]6[α-Mo8O26]3/2}·[Cu（bpe）]3·3H2O[1, bpe=bis（4-pyridyl）ethylene], has been synthesized and structurally characterized. X-Ray diffraction analysis reveals that each α-octamolybdate cluster links six transition metal complex chains and the title compound has represented the highest connective number of M―N chains modified octamolybdate POMs to date. Note that there are two crystallographically unique [α-Mo8O26]n- clusters and eight unique copper sites, which play an important role in the overall architecture of hybrid compounds. Additionally, the electrochemical properties of the title compound were studied.

Hydrothermal Synthesis and Crystal Structure of a Hybrid Compound Based on β-Octamolybdate [Mn(2,2’-bipy)_3]_2[β-Mo_8O_(26)]·4H_2O

A hybrid compound [Mn（2,2＇-bipy）3]2[β-Mo8O26]·4H2O prepared by the hydrothermal method consists of a [β-Mo8O26]^4- isopolyanion, two isolated manganese-bipyridyl units [Mn（2,2＇-bipy）3]^2＋ and four crystal water molecules. Each [Mn（2,2＇-bipy）3]^2＋ is defined by six nitrogen atoms from three 2,2＇-bipyridine molecules forming a distorted MnN6 octahedron. Crystallographic data for the title compound： monoclinic, space group P21/c, a = 12.156（2）, b = 13.738（3）, c = 21.949（4） A,β = 90.44（3）°, V = 3665.3（13） A^3, Mr = 2302.57, Z = 2, Dc = 2.086 g/cm^3, F（000） = 2252, T= 293（2） K,μ（Mo-Kα） = 1.745 mm^-1, R = 0.0436, wR = 0.1056, and GOF = 1.074 for 550 parameters and 5515 observed reflections with I 〉 2σ（I）.

The First Example of a Supramolecular Structure Containing [2-(1H-Pyrazol-3-yl)-pyridine] Complex and both α-and β-Octamolybdates

The title compound, [Ni（C8N3H7）3]4[Mo8O26]2·6H2O 1, has been synthesized from the reaction of 2-（1H-pyrazol-3-yl）-pyridine （L） with （NH4）2MoO4·2H2O and NiCl2·6H2O. Elemental analysis, IR, UV spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure of the compound. Crystal data： C96H96Mo16N36Ni4O58, Mr = 4451.97, monoclinic system, space group P21/n, a = 20.846（5）, b = 14.825（5）, c = 23.122（5） A ,β= 91.594（5）°, V = 7143（3）A^3, Z = 2, F（000） = 4344, Dc = 2.070 g/cm^3,μ = 1.968 mm^-1, R = 0.0452 and wR = 0.1056 for 17102 independent reflections （Rint = 0.0442） and 11074 observed reflections （I 〉 2σ（I））. Structural analysis indicates that two kinds of octamolybdates （[α-Mo8026]^4- and [β-Mo8026]^4-） co-exist in the compound. This is the first example of a supramolecular structure containing L complex as well as both α- and β-octamolybdate clusters.

Synthesis and Crystal Structure of Tetraimidazolium Dinicotinatooctamolybdate

The title compound, [C3H5N2]4[(C6H5NO2)2(Mo8O26)] 1, was synthesized by the reaction of H2MoO4, nicotinic acid and imidazole in aqueous solution. Single-crystal X-ray analysis has revealed that compound 1 (C24H30Mo8N10O30) crystallizes in the monoclinic system, space group P21/n, Mr = 1706.10, a = 12.529(1), b = 12.796(1), c = 14.038(1) , b = 100.2(1), V = 2215.3(2) 3, Z = 2, Dc = 2.558 g/cm3, F(000) = 1640, = 2.299 mm-1, the final R = 0.0527 and wR = 0.0964 for 3064 observed reflections with I > 2s(I). X-ray crystal structure analysis suggests that compound 1 consists of centrosymmetric dinicotinatooctamolybdate anion and four protonated imidazole cations, which are linked into a three-dimensional framework through hydrogen bonding.

Synthesis and Crystal Structure of a New Imidazole Coordinated Octamolybdate Compound

The title compound (Himi)4[Mo8O26(imi)2]4H2O (imi = imidazole) 1 was synthe- sized by the reaction of H2MoO4 and imidazole in aqueous solution. Single-crystal X-ray analysis reveals that compound 1 is crystallized in the triclinic system, space group P with a = 10.6219(8), b = 10.7260(8), c = 11.3220(9) , a = 92.842(2), b =117.364(1), g = 101.655(1), C18H36Mo8N12- O30, Mr = 1668.11, V = 1106.8(2) 3, Z = 1, Dc = 2.503 g/cm3, F(000) = 804, m = 2.298 mm-1, the final R = 0.0714 and wR = 0.1651 for 3121 observed reflections with I > 2s(I). The X-ray crystal structure analysis suggests that compound 1 is built up by two imidazole ligands coordinated by the centrosymmetric octamolybdate anions, protonated imidazole cations and crystallization water molecules.

A New Coordinated Transition-metal Linked Network Compound Constructed by Octamolybdate Chain

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.

Structure and Two-dimensional Correlation Infrared Spectroscopy Study of a New One-dimensional Chain Compound: (4,4’-Hbpy)_3[NaMo_8O_(26)](4,4’- bpy)_2(H_2O)_4 (bpy = Bipydine)

A novel compound, （4,4＇-Hbpy）3[NaMo8O26]（4,4＇-bpy）2（H2O）4 1 （bpy=bipydine）, was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a=19.1921（5）, b=18.6931（6）, c=9.3821（3） A° β=104.8020（11）°, V=3254.22（17）A°^3 C50H51Mo8N10NaO30, Mr=2062.52, Z=2, F（000）=2016, μ=1.591 mm^-1 and Dc=2.105 g/cm^3. The final R=0.0283 and wR=0.0912 for 3118 observed reflections （I〉20（I））. Compound 1 contains the β-[Mo8O26]^4-anion, sodium ion, 4,4＇-bpy and lattice crystalline water molecules. The β-[MosO26] units link the sodium ion to form a chain structure. The infinitechains of [Na（Mo8O26）]^3- blocks are surrounded by protonized 4,4＇-bpy cations, 4,4＇-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.

Synthesis,Structure and Electrochemical Property of a Supramolecular Compound(H_2en)_2[Cu(en)_2(H_3O)_2][Mo_8O_(28)]

A supramolecular compound（H2en）2[Cu（en）2（H3O）2][Mo8O28]（en=ethylenediamine） was hydrothermally prepared and confirmed by elemental analysis and TG analysis.Single-crystal X-ray analysis reveals that the crystal crystallizes in the triclinic system,space group P1 with a=9.4635（4）,b=9.8645（5）,c=10.9794（5）A,α=69.2050（10）,β=72.3730（10）,γ=78.4510（10）o,Mr=1559.55,V=908.24（7）A^3,Z=1,Dc=2.851 g/m^3,F（000）=749,μ=3.350 mm^-1,S=1.000,the final R=0.0217 and wR=0.0567.The compound consists of（H2en）^2＋,[Mo8O28]^8-anion and [Cu（en）2（H3O）2]^2＋ cations and constructs a 3D supramolecular structure through hydrogen bonds between the nitrogen atoms from en of [Cu（en）2（H3O）2]^4＋ fragments and the terminal oxygen atoms from the [Mo8O28]^8-polyoxoanions.The electrochemical behavior of this compound has been studied in detail based on a solid bulk modified carbon paste electrode of compound（CPE）.

A New One-dimensional Chain Compound Constructed by {Mo_8O_(28)} units via Corner-sharing

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.

Synthesis and Crystal Structure of [H-amp]_4[Mo_8O_(26)(DMF)_2]·2H_2O (amp=2-Amino-6-methyl-pyridine)

The reaction of MoO2(acac)2 with 2-amino-6-methyl-pyridine (amp) in the mixed solvent of DMF (N,N-dimethylformamide) and water affords the title complex [H-amp]4- [Mo8O26(DMF)2]2H2O which was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis with the following crystallographic data: C30H54Mo8N10O30, Mr = 1802.35, monoclinic, P21/n, a = 8.631(1), b = 24.260(3), c = 13.351(2) ? b = 104.688(3), V = 2704.2(7) 3, Z = 2, Dc = 2.213 g/cm3, m =1.890 mm-1 and F(000) = 1760. The final R = 0.0281 and wR = 0.0620 for 4935 observed reflections with I > 2s(I). X-ray structure analysis has confirmed the existence of g-[Mo8O26]4- anion in the molecule. Eight MoO6 distorted octahedra share edges with short terminal MoO bonds from 1.691(3) to 1.749(2) ? medium bonds from 1.868(2) to 1.965(2) ?and long bonds from 2.059(2) to 2.450(2) ? In the terminal site there exist two DMF ligands bound to the Mo atom through O atoms with the MoODMF bond length of 2.166(3) ? affording a bond strength of 0.433. A three-dimensional network structure was formed through hydrogen bonds.

Synthesis and Crystal Structure of H_2Mo_8O_(26)〔(n-Bu)_4N_2〔(CH_3)_2 COHCH_2COCH_3〕_2

The title compound 4 methyl 4 hydroxy 2 pentone is obtained by the condensed reaction of acetone, and co crystallized with octamolybdate anion and tetra butyl ammonium cation. The crystal structure belongs to triclinic system, space group P1 , Mo 8C 44 H 98 O 30 N 2 M r=1902.77, a=11.512(6), b=12.790(3), c=13.395(4), α=65.22(2), β=78.26(4), γ=71.12(3), V=1689(1) 3, Z=1, D x =1\^869g/cm 3, F(000)=950, μ =14.79 cm -1 , final R =0.053 and R w =0.067. The orbital hybridization of C(53) and C(55) are sp 3 and sp 2 separately in (CH 3) 2COHCH 2COCH 3 and the catalysis of β octamolybdate anion might be present for the condensed reaction of acetone.

A High Dimensional Coordination Polymer Based on [β-Mo_8_(O)_(26)]^(4-) Inorganic Building Block: Synthesis, Structure and Topology

A high dimensional copper coordination polymer {[Cu2（btb）2（H2O）4（ -Mo8O26）] H2O}n（1, btb = 1,4-bis（1,2,4-triazol-1-yl）butane） based on [ -Mo8O26]4 anions and flexible bis（triazole） ligands has been synthesized and characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction and thermal analysis. The crystallographic data show that complex 1 crystallizes in triclinic space group P with a = 9.7550（10）, b = 10.3996（11）, c = 10.9516（11）, = 77.622（2）, = 89.602（2）, = 87.610（2）, V = 1084.25（19）3, C16H34Cu2Mo8 N12O31, Mr = 1785.15, Dc = 2.734 g cm 3, μ（MoKα） = 3.303 mm 1, F（000） = 856, GOF = 1.060, Z = 1, the final R = 0.0376 and wR = 0.0982 for I 〉 2 （I）. In 1, the inorganic building block [ -Mo8O26]4 anions are connected with each other to generate one-dimensional chains. Then the chains are further connected by Cu2＋ ions to form a three-dimensional （3D） inorganic framework [Cu2（ -Mo8O26）]n containing quadrangular channels, with the pcu alpha-Po primitive cubic topology. The btb ligands are encapsulated into the void of the 3D inorganic framework forming a new three-dimensional architecture. The thermal analysis illustrates that complex 1 retains a comparatively good thermal stability.

Hydrothermal Synthesis and Structural Characterization of a Novel Organic-Inorganic Hybrid Compound {[Cu(2,2′-bpy)_2]_2-Mo_8O_(26)}

A novel organic-inorganic hybrid compound {[Cu(2,2'-bpy)_2]_2Mo_8O_(26)} hasbeen hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction.The compound crystallizes in the orthorhombic space group, Pna2_1, with a = 2.4164(5), b =1.8281(4), c = 1.1877(2) nm, V = 5.247(2) nm^3, Z = 4, and final R_1 = 0.0331, wR_2 = 0.0727. Thestructure consists of discrete {[Cu(2,2'-bpy)_2]_2Mo_8O_(26)} clusters, constructed from aβ-octamolybdate subunit [Mo_8O_(26)]^(4-) covalently bonded to two [Cu(2,2'-bpy)_2]^(2+)coordination complex cations via bridging oxo groups. In addition, the spectroscopic properties andthermal behavior of this compound have been investigated by spectroscopic techniques (UV-vis, IR,Raman and EPR spectra) and TG analysis.