Structural characterization of CeO(2)-ZrO(2)/TiO(2) and V(2)O(5)/CeO(2)-ZrO(2)/TiO(2) mixed oxide catalysts by XRD, Raman spectroscopy, HREM, and other techniques

Structural characteristics of CeO(2)-ZrO(2)/TiO(2) (CZ/T) and V(2)O(5)/CeO(2)-ZrO(2)/TiO(2) (V/CZ/T) mixed oxide catalysts have been investigated using X-ray diffraction (XRD), BET surface area, Raman spectroscopy (RS), and high-resolution transmission electron microscopy (HREM) techniques. The CeO(2)-ZrO(2) (1:1 mole ratio) solid solution was deposited over a finely powdered TiO(2) support by a deposition precipitation method. A nominal 5 wt % V(2)O(5) was impregnated over the calcined (773 K) CZ/T mixed oxide carrier by a wet impregnation technique. The obtained CZ/T and V/CZ/T samples were further subjected to thermal treatments from 773 to 1073 K to understand the dispersion and temperature stability of these materials. In the case of CZ/T samples, the XRD results suggest the formation of different cubic and tetragonal Ce-Zr-oxide phases, Ce(0.75)Zr(0.25)O(2), Ce(0.6)Zr(0.4)O(2), Ce(0.5)Zr(0.5)O(2), and Ce(0.16)Zr(0.84)O(2) in varying proportions depending on the treatment temperature. With increasing calcination temperature from 773 to 1073 K, the intensity of the lines pertaining to cubic Ce(0.6)Zr(0.4)O(2) and Ce(0.5)Zr(0.5)O(2) phases increased at the expense of cubic Ce(0.75)Zr(0.25)O(2), indicating more incorporation of zirconia into the ceria lattice. The TiO(2) was mainly in the anatase form whose crystallite size also increased with increasing treatment temperature. A better crystallization and more incorporation of zirconia into the ceria lattice was noted when CZ/T was impregnated with V(2)O(5). However, no crystalline V(2)O(5) could be seen from both XRD and RS measurements. In particular, a preferential formation of CeVO(4) compound and an intense tetragonal Ce(0.16)Zr(0.84)O(2) phase were noted beyond 873 K. The HREM results indicate, in the case of CZ/T samples, a well-dispersed Ce-Zr-oxide of the size approximately 5 nm over the bigger crystals ( approximately 40 nm) of TiO(2) when treated at 873 K. The exact structural features of these crystals as determined by digital diffraction analysis of experimental images reveal that the Ce-Zr-oxides are mainly in the cubic fluorite geometry and the TiO(2) is in anatase form. A better crystallization of Ce-Zr-oxides ( approximately 8 nm) over the surface of bigger crystals of TiO(2) was noted at 1073 K. A further enhancement in the crystallite size and zirconia-rich tetragonal phase was noted in the case of V/CZ/T samples. Further, the structure of CeVO(4) formed was also clearly identified in conformity with XRD and RS results.     

Ni（bpy）（H2O）（V2O6）和[Ni（bpy）2]2（V6O17）的水热合成与晶体结构

用NiCl2·6H2O,2,2＇-联吡啶（bpy）,NH4VO3,WO3在443K下通过水热反应法得到了两种多钒酸镍配合物Ni（bpy）（H2O）（V2O6）（1）和[Ni（bpy）2]2（V6O17）（2）．单晶X射线衍射结果表明化合物（1）属于正交晶系,空间群为Pcα2（1）,晶胞参数为0=0．91704（18）nm,b=1．0519（2）nm,c=1．4336（3）nm,V=1．3830（5）nm^3,Z=4;化合物（2）属于单斜晶系,空间群为P2（1）／c,晶胞参数为α=1．5467（3）nm,b=1．4740（3）nm,c=1．0457（2）nm,β=91．99（3）°,V=2．3826（8）nm^3,Z=4．化合物（1）由2,2’-联吡啶修饰的二维[Ni（V2O6）（H2O）]∞电中性层构成,而化合物（2）则由2,2＇-联吡啶修饰的、呈正弦波浪状的[Ni：（V6O17）]∞二维电中性层构成．     

Structural Studies of [V_2S_6O_2(CuPPh_3)_4(CuMeCN)_2]·2CH_2Cl_2·2PrOH

ＳｔｒｕｃｔｕｒａｌＳｔｕｄｉｅｓｏｆ［Ｖ_２Ｓ_６Ｏ_２（ＣｕＰＰｈ_３）_４（ＣｕＭｅＣＮ）_２］·２ＣＨ_２Ｃｌ_２·２ＰｒＯＨＺＨＡＮＧＨａｎ－Ｈｕｉ；ＹＵＸｉｕ－Ｆｅｎ；ＹＡＮＧＲｏｎｇ－Ｓｈｅｎｇ；ＺＨＥＮＧＦａ－Ｋｕｎ；ＨＵＡＮＧＬｉａｏ－Ｙｕ...     

Vibrational analysis of Ag3(PO2NH)3, Na3(PO2NH)3 x H2O, Na3(PO2NH)3 x 4H2O,

FT IR and FT Raman spectra of Ag3(PO2NH), (Compound 1), Na3(PO2NH)3 x H2O (Compound II), Na3(PO2NH)3 x 4H2O (Compound III), [C(NH2)3]3(PO2NH)3 x H2O (Compound IV) and (NH4)4(PO2NH)4 x 4H2O (Compound V) are recorded and analyzed on the basis of the anions, cations and water molecules present in each of them. The PO2NH- anion ring in compound I is distorted due to the influence of Ag+ cation. Wide variation in the hydrogen bond lengths in compound III is indicated by the splitting of the v2 and v3 modes of vibration of water molecules. The NH4 ion in compound V occupies lower site symmetry and exhibits hindered rotation in the lattice. The correlations between the symmetric and asymmetric stretching vibrations of P-N-P bridge and the P-N-P bond angle have also been discussed.     

Crystal structure and spectroscopic characterization of K8(VO)2O(SO4)6

Red and yellow dichroistic crystals of a vanadium(V) compound, potassium (mu-oxo, di-mu-sulfato)bis(oxodisulfatovanadate), K(8)(VO)(2)O(SO(4))(6), have been obtained from the ternary catalytic model melt system K(2)S(2)O(7)[bond]K(2)SO(4)[bond]V(2)O(5). By slow cooling of the melt from 420 to 355 degrees C, crystal growth occurred, using solid V(2)O(5) crystals present in the melt as nucleation promoter. The compound crystallizes in the monoclinic space group P2(l) with a = 13.60(9) A, b = 13.93(9) A, c = 14.05(9) A, beta = 90.286(10) degrees, and Z = 2. It contains two VO(6) octahedra linked together by a mu-oxo and two mu-sulfato bridges. Furthermore, each octahedron has two monodentate sulfate ligands, making the dimeric entity coordinatively saturated. IR spectroscopy shows bands arising from V[bond]O[bond]V and V[double bond]O stretches as well as splitting of sulfate bands due to the different degrees of freedom present for different conformations of sulfate ligands. The coordination of vanadium in K(8)(VO)(2)O(SO(4))(6) is discussed in relation to the reaction mechanism of SO(2) oxidation catalysis.     

Synthesis, Crystal Structure and Spectral Properties of [Ce(NO_3)_5(H_2O)_2]·2(Hphen)·(H_2O)

1 INTRODUCTION Recently, the ternary or quaternary mixed anion complexes of cerium(III) containing 1,10-phenanthroline (phen) have attracted considerable attention due to their rich structural chemistry and appealing magnetic properties[1]. Panagiotopou…     

Synthesis, Structure, and Magnetic Properties of One Polyoxometalate (W/Mo) Compound: H_8K{[Ni(H_2O)_5]_2(H_2Mo_(1.80)W_(10.20)O_(42))}Cl_3·16H_2O

One new polyoxometalate compound connected via nickel/potassium cations, H8K{[Ni(H2O)5]2(H2Mo1.80W10.20O42)}Cl3·16H2O 1, was prepared and characterized by elemental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis results reveal that clusters of [Ni(H2O)5]2(H2Mo1.80W10.20O42)}6-in compound 1 are linked by potassium cations to form one- dimiensional chains, based on which a three-dimensional network is further constructed via the hydrogen bonds of O…O and O…Cl. Magnetic measurements show that compound 1 has para- magnetic properties. Crystal data: H62Cl3KMo1.80Ni2O68W10.20, Mr = 3461.33, monoclinic, space group C2/c, a = 18.9291(19), b = 16.6758(17), c = 19.1064(19), β = 106.6880(10)°, V = 5777.1(10)3, Z = 4, Dc = 3.980 g/cm3, F(000) = 6250, μ = 21.574 mm?1, R = 0.0579 and wR = 0.1623 (I > 2σ(I)).     

Crystal structure and spectroscopic properties of Na(2)K(6)(VO)(2)(SO(4))(7)

Red-brown crystals of a new mixed alkali oxo sulfato vanadium(V) compound Na(2)K(6)(VO)(2)(SO(4))(7), suitable for X-ray determination, have been obtained from the catalytically important binary molten salt system M(2)S(2)O(7)-V(2)O(5) (M = 80% K and 20% Na). By slow cooling of a mixture with the mole fraction X(V(2)O(5)) = 0.24 from 325 degrees C, i.e., just below the liquidus temperature, to the solidus temperature of around 300 degrees C, a dark reddish amorphous phase was obtained containing crystals of the earlier described V(V)-V(IV) mixed valence compound K(6)(VO)(4)(SO(4))(8) and Na(2)K(6)(VO)(2)(SO(4))(7) described here. This compound crystallizes in the tetragonal space group P4(3)2(1)2 (No. 96) with a = 9.540(3) A, c = 29.551(5) A at 20 degrees C and Z = 4. It contains a distorted VO(6) octahedron with a short V-O bond of 1.552(6) A, a long one of 2.276(5) A trans to this, and four equatorial V-O bonds in the range 1.881(6)-1.960(6) A. The deformation of the VO(6) octahedron is less pronounced compared to that of the known oxo sulfato V(V) compounds. Each VO(3+) group is coordinated to five sulfate groups of which two are unidentately coordinated and three are bidentate bridging to neighboring VO(3+) groups. The length of the S-O bonds in the S-O-V bridges of the two unidentately coordinated sulfato groups are 1.551(6) A and 1.568(6) A, respectively, which are unusually long compared to our earlier measurements of sulfate groups in other V(III), V(IV), and V(V) compounds.     

Pillared layered structures based upon M(III) ethylene diphosphonates: the synthesis and crystal structures of M(III)(H(2)O)(HO(3)P(CH(2))(2)PO(3)) (M = Fe, Al, Ga)

A three-dimensional iron(III) diphosphonate, Fe(III)(H(2)O)(HO(3)P(CH(2))(2)PO(3)), I, has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pbca (no. 61) where a = 9.739(5) A, b = 9.498(5) A, c = 15.940(8) A, V = 1474.4(1) A(3), Z = 8, and R(1) = 0.0380. The structure consists of inorganic sheets pillared by the 1,2-ethylenediphosphonate groups. The sheets are composed of Fe(H(2)O)O(5) octahedra connected through PO(3)C tetrahedra. The corresponding isostructural aluminum (II) and gallium (III) compounds were also synthesized and indexed: II, a = 9.534(1) A, b = 9.255(2) A, c = 15.724(1) A, V = 1387.5(1) A(3); III, a = 9.670(1) A, b = 9.357(2) A, c = 15.862(4) A, V = 1435.4(1) A(3).     

New vanadium phosphate ([(phen)VIVO]2(VV2O5)(HPO4))n with chiral layer architecture

A new layered vanadium phosphate ([(phen)V(IV)O](2)(V(V)(2)O(5))(HPO(4))n has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, and single-crystal X-ray diffraction. This compound crystallized in the monoclinic space group P2/c with a = 9.979(2) A, b = 9.886(2) A, c = 15.298(3) A, beta = 102.86(3) degrees, V = 1471.3(5) A(3), and Z = 4. In the structure of this compound, two nitrogen atoms of 1,10-phen are directly coordinated to the vanadium skeleton. Interestingly, the crystal structure consists of two types of chiral layers, one left-handed and the other right-handed, which lead to a racemic solid-state compound. In each layer, there coexist three distinct rings, described as a 8-membered ring [V(2)(oct)P(2)O(4)], 12-membered ring [V(2)(omicron)(ct)V(2)(tet)P(2)O(6)], and 16-membered ring [V(2)(omicron)(ct)V(4)(tet)P(2)O(8)].     

New Layered Polyborates Cs(2)M(2)B(10)O(17) (M = Na, K)

The polyborates Cs(2)M(2)B(10)O(17) (M = Na, K) have been prepared and their structures determined by single-crystal X-ray diffraction methods. They crystallize in the monoclinic space group C2/c (Z = 8) with unit-cell parameters a = 21.643(3) ?, b = 6.558(2) ?, c = 11.072(2) ?, beta = 105.43(1) degrees, V = 1514.8(6) ?(3) for the Na compound and a = 22.547(9) ?, b = 6.614(2) ?, c = 11.288(4) ?, beta = 103.25 degrees, V = 1638.3(8) ?(3) for the K analogue. The new structural type contains a 2-dimensional borate matrix that is built from a complete condensation of the ring system B(5)O(11). The Cs atoms reside within the borate matrix, and the Na (K) atoms are placed between the thick Cs borate sheets.     

{(Mo)Mo5O21(H2O)3(SO4)}12(VO)30(H2O)20]36-: a molecular quantum spin icosidodecahedron

Self-assembly of aqueous solutions of molybdate and vanadate under reducing, mildly acidic conditions results in a polyoxomolybdate-based {Mo72V30} cluster compound Na8K16(VO)(H2O)5[K10 subset{(Mo)Mo5O21(H2O)3(SO4)}12(VO)30(H2O)20].150H2O, 1, a quantum spin-based Keplerate structure.     

AVSeO(5) (A = Rb, Cs) and AV(3)Se(2)O(12) (A = K, Rb, Cs, NH(4)): Hydrothermal Synthesis in the V(2)O(5)-SeO(2)-AOH System and Crystal Structure of CsVSeO(5)

Hydrothermal reactions in the V(2)O(5)-SeO(2)-AOH systems (A = Na, K, Rb, Cs, NH(4)) were studied with various reagent mole ratios. Typical millimole ratios were V(2)O(5)/SeO(2)/AOH = 5 or 3/15/x in 10-mL aqueous solutions, where x was 5, 10, 15, and 20. The reactions with x = 5 for A = K, Rb, Cs, and NH(4) at 230 degrees C produced single-phase products of the general formula AV(3)Se(2)O(12) with the (NH(4))(VO)(3)(SeO(3))(2) structure type. The x = 15 reactions for A = Rb and Cs yielded AVSeO(5) phases with a new structure type. The crystal structure for CsVSeO(5) was determined with X-ray single-crystal diffraction techniques to be monoclinic (P2(1) (No. 4), a = 7.887(3) ?, b = 7.843(2) ?, c = 9.497(3) ?, beta = 92.13(3) degrees, Z = 4). The structure of this compound consists of interwoven helixes extended in all three directions. The spires are composed of alternating SeO(3) and VO(5) units sharing common-edge oxygens in all three directions. For A = K and NH(4), the reactions of this mole ratio did not produce any identifiable phases. Each of the compounds is characterized by powder X-ray diffraction, infrared spectroscopic, and thermogravimetric techniques. The dependency of the synthesis results on the reaction conditions is discussed and rationalized.     

SYNTHESIS, STRUCTURE AND PROPERTIES OF Na_3[V_2O_3(nta)_2]·5H_2O

<正> Compound Na3 [V2O3 (nta )2 ]·5H2O (1) (ntaH3 = N (CH2CO2H)3) has been prepared by reduction of a mixture of (NH4)2[VO(O2)2Cl] and H3(nta) in H2O with Na2S2O4. The compound crystallizes in the triclinic system, space group P1 with Mr = 685. 2, a = 11. 050(6), b=12. 179(4), c=9. 792 (3)A,α=111.71(2),β= 98. 23(3), γ= 89. 36(2)°, Z=2, V = 1210. 5A3,λ(MoKa) = 0. 71069 A, F(000) = 694 and DC = 1. 880g/cm3. The structure was solved by direct methods and refined by full-matrix least squares to final R and Rw values of 0. 055 and 0. 065, respectively.The structure of the anion can be considered as two [VO(nta)] fragments connected by one μ2-O atom. Each vanadium atom in the fragment is coordinated by one vanadyl oxygen atom, one bridging-oxygen atom, three oxygen atoms and one nitrogen atom from (nta) ligand in a distorted octahedral geometry. In this paper, we have studied the conversion of compound 1 to mononuclear compound Na2[VO(O2) (nta)]·5H2O (2) by oxidation with hydrogen peroxide, as well as thei     

Synthesis and characterization of the layered vanadium borophosphate (imidazolium)3.8(H3O)1.2[(VO)4(BO)2(PO4)5].0.3H2O

The first layered vanadium borophosphate (imidazolium)3.8(H3O)1.2[(VO)4(BO)2(PO4)5].0.3H2O (1) has been synthesized hydrothermally and characterized by chemical analysis, infrared and Raman spectroscopy, and thermogravimetric and magnetic measurements. The compound crystallizes in the monoclinic space group C2/c, a = 9.4737 (5) A, b = 22.1444 (12) A, c = 17.2192 (13) A, beta = 105.936 (1) degrees, Z = 4. The structure contains a novel borophosphate secondary building unit, [B2P5O22], in which two BP2O10 trimers are linked by an additional PO4 tetrahedron. These units are connected by V(IV)2O8 dimers and V(IV)O5 square pyramids to form layers. The space between the layers is filled by disordered imidazolium and hydronium cations and water molecules that form a complex network of hydrogen bonds. A model for the interlayer disorder is proposed.     

二维层状水合酸式硫酸铈H3O[Ce(SO4)2·(H2O)3]·H2O的水热合成与结构表征

镧系金属硫酸盐由于在稀土分离等方面具有重要的应用而受到广泛关注。但是，因其适于结构测定的单晶相对难以得到，迄今，关于稀土硫酸盐的结构报道仍然较少，且主要局限于水合硫酸盐和三元硫酸盐．近几年中，基于硫酸根与磷酸根在结构上的相似性，借鉴在水热／溶剂热体系中采用有机胺作模板剂大量合成具有空旷骨架结构的微孔磷酸盐的成功经验，以有机胺为模板剂合成具有空旷骨架结构的镧系金属硫酸盐的工作也已见诸报道．在这些化合物中，由于硫酸根配位方式的多样性和稀土元素配位数和配位构型的可调变性，展现出了一些有趣的结构特征．     

Two new neptunyl(V) selenites: a novel cation-cation interaction framework in (NpO2)3(OH)(SeO3)(H2O)2 3H2O and a uranophane-type sheet in Na(NpO2)(SeO3)(H2O)

Dark green crystals of (NpO(2))(3)(OH)(SeO(3))(H(2)O)(2)·H(2)O (1) have been prepared by a hydrothermal reaction of neptunyl(V) and Na(2)SeO(4) in an aqueous solution at 150 °C, while green plates of Na(NpO(2))(SeO(3))(H(2)O) (2) have been synthesized by evaporation of a solution of neptunyl(V), H(2)SeO(4), and NaOH at room temperature. Both compounds have been characterized by single-crystal X-ray diffraction. The structure of compound contains three crystallographically unique Np atoms that are bonded to two O atoms to form a nearly linear O═Np═O NpO(2)(+) cation. Neighboring Np(5+) ions connect to each other through a bridging oxo ion from the neptunyl unit, a configuration known as cation-cation interactions (CCIs), to build a complex three-dimensional network. More specifically, each Np(1)O(2)(+), Np(2)O(2)(+), and Np(3)O(2)(+) cation is involved in three, five, and four CCIs with other units, respectively. The framework of neptunyl(V) pentagonal bipyramids is decorated by selenite trigonal pyramids with one-dimensional open channels where uncoordinated waters are trapped via hydrogen bonding interactions. Compound adopts uranophane-type [(NpO(2))(SeO(3))](-) layers, which are separated by Na(+) cations and water molecules. Within each layer, neptunyl(V) pentagonal bipyramids share equatorial edges with each other to form a single chain that is further connected by both monodentate and bidentate selenite trigonal pyramids. Crystallographic data: compound, monoclinic, P2(1)/c, Z = 4, a = 6.6363(8) ?, b = 15.440(2) ?, c = 11.583(1) ?, β = 103.549(1)°, V = 1153.8(2) ?(3), R(F) = 0.0387 for I > 2σ(I); compound (2), monoclinic, C2/m, Z = 4, a = 14.874(4) ?, b = 7.271(2) ?, c = 6.758(2) ?, β = 112.005(4)°, V = 677.7(3) ?(3), R(F) = 0.0477 for I > 2σ(I).     

二维网状结构超分子化合物[Cu(dafo)_2(H_2O)_2](ClO_4)_2的合成和晶体结构

试图用4,5-二氮芴-9-酮(dafo)、邻苯二甲酸、高氯酸铜合成二价铜的混配体超分子化合物时得到一亮蓝色棱状晶体[Cu(dafo)2(H2O)2](ClO4)2,其结构通过单晶X-射线衍射法确定。该化合物是单斜晶系,空间群为P21/n。晶胞参数:a = 7.947(3),b = 12.021(5),c = 13.190(5) 牛? = 90.000(6)埃?V = 1260.0(9) ?,Z = 2,F(000) = 670,Mr = 662.83,Dc = 1.747 g/cm3,(MoK? = 1.154 mm-1,R = 0.0455,wR = 0.1041。单晶结构分析表明该超分子化合物具有二维网状结构,该结构是通过氢键这种弱相互作用形成的。     

Synthesis, Structure, and Magnetic Properties of One Polyoxometalate (W/Mo) Compound: H8K{[Ni(H2O)5]2(H2Mo1.80W10.20O42)}Cl3·16H2O

One new polyoxometalate compound connected via nickel/potassium cations, H8K{[Ni(H2O)5]2(H2Mo1.80W10.20O42)}Cl3·16H2O 1, was prepared and characterized by elemental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis results reveal that clusters of [Ni(H2O)5]2(H2Mo1.80W10.20O42)}6-in compound 1 are linked by potassium cations to form one- dimiensional chains, based on which a three-dimensional network is further constructed via the hydrogen bonds of O…O and O…Cl. Magnetic measurements show that compound 1 has para- magnetic properties. Crystal data: H62Cl3KMo1.80Ni2O68W10.20, Mr = 3461.33, monoclinic, space group C2/c, a = 18.9291(19), b = 16.6758(17), c = 19.1064(19)(A), β = 106.6880(10)(, V = 5777.1(10) (A)3, Z = 4, Dc = 3.980 g/cm3, F(000) = 6250, μ = 21.574 mm(1, R = 0.0579 and wR = 0.1623 (Ⅰ ＞ 2σ(I)).     

(C5H7N2)3(AsMo12O40)·3C5H6N2·2H2O的水热合成、晶体结构及催化性能

采用水热法合成了一种新的3-氨基吡啶砷钼多金属氧酸盐配合物(C5H7N2)3(AsMo12O40)·3C5H6N2·2H2O。 通过单晶X射线衍射、红外光谱、紫外光谱和差热-热重对其进行了表征。 用催化消除丙酮的反应为模式反应,测试了配合物的催化性能。 研究结果表明,标题配合物是由Keggin结构[AsMo12O40]3-杂多阴离子、[C5H7N2]+阳离子、[C5H6N2]分子和结晶水分子组成。 配合物属于单斜晶系,P21/n空间群;晶胞参数a=1.33820(12) nm,b=2.2542(2) nm,c=1.9848(2) nm,β=100.27(3)°,V=5.8912(10) nm3,Z=4,Rgt(F)=0.0590,wRref(F2)=0.1882。 配合物对催化消除丙酮具有较好的的活性,催化实验结果表明,160 ℃下,0.20 g的催化剂可将初始浓度均为1.3 g/m3,流速为4.5 mL/min的丙酮完全消除。