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1.
Two new niobium phosphates were synthesized and their crystal structures determined from single-crystal X-ray data. [NbOF(PO4)](N2C5H7) (1) (monoclinic, space group P21/c, a=11.442(1), b=9.1983(7), c=9.1696(8) Å, β=109.94(1)°) has a layered structure and is the first example of a negatively charged NbOF(PO4) layer analogous to the MO(H2O)PO4 (M=V, Nb) layers. The layer charge is compensated by interlayer 4-aminopyridnium cations that adopt an unusual arrangement as a consequence of H-bonding and π-π interactions. The interlayer aminopyridnium cations can be exchanged with alkylammonium ions which form bilayers inclined at ∼65° to the NbOF(PO4) layer. [(Nb0.9V1.1)O2(PO4)2(H2PO4)] (N2C2H10) (2) (orthorhombic, space group Pbca, a=15.821(2),b=9.0295(9),c=18.301(2) Å) has a disordered three-dimensional structure based on NbO(PO4) layers cross-linked by phosphate tetrahedra, and has a similar structure to the known vanadium analog [V2O2(PO4)2(H2PO4)] (N2C2H10).  相似文献   

2.
Three new compounds Ca(HF2)2, Ba4F4(HF2)(PF6)3 and Pb2F2(HF2)(PF6) were obtained in the system metal(II) fluoride and anhydrous HF (aHF) acidified with excessive PF5. The obtained polymeric solids are slightly soluble in aHF and they crystallize out of their aHF solutions. Ca(HF2)2 was prepared by simply dissolving CaF2 in a neutral aHF. It represents the second known compound with homoleptic HF environment of the central atom besides Ba(H3F4)2. The compounds Ba4F4(HF2)(PF6)3 and Pb2F2(HF2)(PF6) represent two additional examples of the formation of a polymeric zigzag ladder or ribbon composed of metal cation and fluoride anion (MF+)n besides PbF(AsF6), the first isolated compound with such zigzag ladder. The obtained new compounds were characterized by X-ray single crystal diffraction method and partly by Raman spectroscopy. Ba4F4(HF2)(PF6)3 crystallizes in a triclinic space group P1¯ with a=4.5870(2) Å, b=8.8327(3) Å, c=11.2489(3) Å, α=67.758(9)°, β=84.722(12), γ=78.283(12)°, V=413.00(3) Å3 at 200 K, Z=1 and R=0.0588. Pb2F2(HF2)(PF6) at 200 K: space group P1¯, a=4.5722(19) Å, b=4.763(2) Å, c=8.818(4) Å, α=86.967(10)°, β=76.774(10)°, γ=83.230(12)°, V=185.55(14) Å3, Z=1 and R=0.0937. Pb2F2(HF2)(PF6) at 293 K: space group P1¯, a=4.586(2) Å, b=4.781(3) Å, c=8.831(5) Å, α=87.106(13)°, β=76.830(13)°, γ=83.531(11)°, V=187.27(18) Å3, Z=1 and R=0.072. Ca(HF2)2 crystallizes in an orthorhombic Fddd space group with a=5.5709(6) Å, b=10.1111(9) Å, c=10.5945(10) Å, V=596.77(10) Å3 at 200 K, Z=8 and R=0.028.  相似文献   

3.
Two new potassium uranyl molybdates K2(UO2)2(MoO4)O2 and K8(UO2)8(MoO5)3O6 have been obtained by solid state chemistry . The crystal structures were determined by single crystal X-ray diffraction data, collected with MoKα radiation and a charge coupled device (CCD) detector. Their structures were solved using direct methods and Fourier difference techniques and refined by a least square method on the basis of F2 for all unique reflections, with R1=0.046 for 136 parameters and 1412 reflections with I?2σ(I) for K2(UO2)2(MoO4)O2 and R1=0.055 for 257 parameters and 2585 reflections with I?2σ(I) for K8(UO2)8(MoO5)3O6. The first compound crystallizes in the monoclinic symmetry, space group P21/c with a=8.250(1) Å, b=15.337(2) Å, c=8.351(1) Å, β=104.75(1)°, ρmes=5.22(2) g/cm3, ρcal=5.27(2) g/cm3 and Z=4. The second material adopts a tetragonal unit cell with a=b=23.488(3) Å, c=6.7857(11) Å, ρmes=5.44(3) g/cm3, ρcal=5.49(2) g/cm3, Z=4 and space group P4/n.In both structures, the uranium atoms adopt a UO7 pentagonal bipyramid environment, molybdenum atoms are in a MoO4 tetrahedral environment for K2(UO2)2(MoO4)O2 and MoO5 square pyramid coordination in K8(UO2)8(MoO5)3O6. These compounds are characterized by layered structures. The association of uranyl ions (UO7) and molybdate oxoanions MoO4 or MoO5, give infinite layers [(UO2)2(MoO4)O2]2− and [(UO2)8(MoO5)3O6]8− in K2(UO2)2(MoO4)O2 and K8(UO2)8(MoO5)3O6, respectively. Conductivity properties of alkali metal within the interlayer spaces have been measured and show an Arrhenius type evolution.  相似文献   

4.
Crystal structures of Pb(MoO2)2(PO4)2 and Ba(MoO2)2(PO4)2 were determined. Both compounds contain the molybdyl group MoO2. The monoclinic unit-cell parameters are a = 6.353(7), b = 12.289(4), c = 11.800 Å, β = 92°56(6), and Z = 4 for the lead salt and a = 6.383(8), b = 7.142(7), c = 9.953(8) Å, β = 95°46(8), and Z = 2 for the barium salt. P21c is the common space group. The R values are respectively R = 0.027 and R = 0.031 for 1964 and 1714 independent reflections. The frameworks built up by a three-dimensional network of monophosphate PO4 and molybdyl MoO2 groups are similar, characterized mainly by corner-sharing PO4 and MoO6 polyhedra. Two oxygen atoms of each MoO6 group are bonded to the molybdenum atom only as in other molybdyl salts.  相似文献   

5.
α-Ca3(BN2)2 crystallizes in the cubic system (space group: ) with one type of calcium ions disordered over of equivalent (8c) positions. An ordered low-temperature phase (β-Ca3(BN2)2) was prepared and found to crystallize in the orthorhombic system (space group: Cmca) with lattice parameters: , , and . Structure refinements on the basis of X-ray powder data have revealed that orthorhombic β-Ca3(BN2)2 corresponds to an ordered super-structure of cubic α-Ca3(BN2)2. The space group Cmca assigned for β-Ca3(BN2)2 is derived from by a group-subgroup relationship.DSC measurements and temperature-dependent in situ X-ray powder diffraction studies showed reversible phase transitions between β- and α-Ca3(BN2)2 with transition temperatures between 215 and 240 °C.The structure Sr3(BN2)2 was reported isotypic with α-Ca3(BN2)2 () with one type of strontium ions being disordered over of equivalent (2c) positions. In addition, a primitive () structure has been reported for Sr3(BN2)2. Phase stability studies on Sr3(BN2)2 revealed a phase transition between a primitive and a body-centred lattice around 820 °C. The experiments showed that both previously published structures are correct and can be assigned as α-Sr3(BN2)2 (, high-temperature phase), and β-Sr3(BN2)2 (, low-temperature phase).A comparison of Ca3(BN2)2 and Sr3(BN2)2 phases reveals that the different types of cation disordering present in both of the cubic α-phases () have a directing influence on the formation of two distinct (orthorhombic and cubic) low-temperature phases.  相似文献   

6.
A new open-framework compound, [C6H14N2][(UO2)4(HPO4)2(PO4)2(H2O)]·H2O, (DUP-1) has been synthesized under mild hydrothermal conditions. The resulting structure consists of diprotonated DABCOH22+ (C6H14N22+) cations and occluded water molecules occupying the channels of a complex uranyl phosphate three-dimensional framework. The anionic lattice contains uranophane-like sheets connected by hydrated pentagonal bipyramidal UO7 units. [C6H14N2][(UO2)4(HPO4)2(PO4)2(H2O)]·H2O possesses five crystallographically unique U centers. U(VI) is present here in both six- and seven-coordinate environments. The DABCOH22+ cations are held within the channels by hydrogen bonds to both two uranyl oxygen atoms and a μ2-O atom. Crystallographic data (193 K, Mo Kα, λ=0.71073 Å): DUP-1, monoclinic, P21/n, a=7.017(1) Å, b=21.966(4) Å, c=17.619(3) Å, β=90.198(3)°, Z=4, R(F)=4.76% for 382 parameters with 6615 reflections with I>2σ(I).  相似文献   

7.
The structures of the oxyorthogermanate La2(GeO4)O and the apatite-structured La9.33(GeO4)6O2 have been refined from powder neutron diffraction data. La2(GeO4)O crystallizes in a monoclinic unit cell (P21/c) and is cation stoichiometric in contrast to previous reports. La9.33(GeO4)6O2 crystallizes in a hexagonal unit cell (P63/m) and the powder diffraction data show anisotropic peak broadening that is observed in electron diffraction patterns as incommensurate diffuse spots at hkq reciprocal planes (with q=1.6-1.7) and can be attributed to a correlated disorder in the “apatite channels”. This compound was doped up to a nominal composition close to M2La8(GeO4)6O2 with M=Ca, Sr, Ba. The dopant ions preferentially occupy the 4f sites as the number of La vacancies decreases. The measured ionic conductivity of La9.33(GeO4)6O2 is about 3 orders of magnitude larger than for La2(GeO4)O at high temperatures and decreases with increasing dopant content from the highest value of about 0.16 S cm−1 at 1160 K.  相似文献   

8.
The objective of the present work was to synthesize mononuclear ruthenium complex [RuCl2(CO)2{Te(CH2SiMe3)2}2] (1) by the reaction of Te(CH2SiMe3)2 and [RuCl2(CO)3]2. However, the stoichiometric reaction affords a mixture of 1 and [RuCl2(CO){Te(CH2SiMe3)2}3] (2). The X-ray structures show the formation of the cis(Cl), cis(C), trans(Te) isomer of 1 and the cis(Cl), mer(Te) isomer of 2. The 125Te NMR spectra of the complexes are reported. The complex distribution depends on the initial molar ratio of the reactants. With an excess of [RuCl2(CO)3]2 only 1 is formed. In addition to the stoichiometric reaction, a mixture of 1 and 2 is observed even when using an excess of Te(CH2SiMe3)2. Complex 1 is, however, always the main product. In these cases the 125Te NMR spectra of the reaction solution also indicates the presence of unreacted ligand.  相似文献   

9.
Ag4(Mo2O5)(SeO4)2(SeO3) has been synthesized by reacting AgNO3, MoO3, and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO22+ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C2 distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C2 distortion. Upon heating Ag4(Mo2O5)(SeO4)2(SeO3) looses SeO2 in two distinct steps to yield Ag2MoO4. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) Å, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag2(MoO3)3SeO3 was synthesized by reacting AgNO3 with MoO3, SeO2, and HF under hydrothermal conditions. The structure of Ag2(MoO3)3SeO3 consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO6 units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): monoclinic, space group P21/n, a=7.7034(5), b=11.1485(8), c=12.7500(9) Å, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag2(MoO3)3SeO3 decomposes to Ag2Mo3O10 on heating above 550 °C.  相似文献   

10.
The crystal structures of (Ti1?xScx)2O3, x = 0.0038, 0.0109, and 0.0413, and of (Ti0.99Al0.01)2O3, have been determined from X-ray diffraction data collected from single crystals using an automated diffractometer, and have been refined to weighted residuals of 25–34. Cell constants have also been determined for x = 0.0005, 0.0019, and 0.0232. The compounds are rhombohedral, space group R3c, and are isomorphous with α-Al2O3. The hexagonal cell dimensions range from a = 5.1573(2)Å, c = 13.613(1)Å for (Ti0.9995Sc0.0005)2O3 to a = 5.1659(4)Å, c = 13.644(1)Å for (Ti0.9587Sc0.0413)2O3, and a = 5.1526(2)Å, c = 13.609(1)Å for (Ti0.99Al0.01)2O3. Sc and Al substitution cause similar increases in the short near-neighbor metal-metal distance across the shared octahedral face; for Sc doping the increase is from 2.578(1) Å in pure Ti2O3 to 2.597(1) Å in (Ti0.9587Sc0.0413)2O3. By contrast, changes in the metal-metal distance across the shared octahedral edge appear to be governed by ionic size effects. The distance increases from 2.994(1) Å in Ti2O3 to 3.000(1) Å in (Ti0.9587Sc0.0413)2O3 and decreases to 2.991(1) Å in (Ti0.99Al0.01)2O3.  相似文献   

11.
Two new mixed organic-inorganic uranyl molybdates, (C6H14N2)3[(UO2)5(MoO4)8](H2O)4 (1) and (C2H10N2)[(UO2)(MoO4)2] (2), have been obtained by hydrothermal methods. The structure of 1 [triclinic, , Z=1, a=11.8557(9), b=11.8702(9), c=12.6746(9) Å, α=96.734(2)°, β=91.107(2)°, γ=110.193(2)°, V=1659.1(2) Å] has been solved by direct methods and refined on the basis of F2 for all unique reflections to R1=0.058, which was calculated for the 5642 unique observed reflections (|Fo|?4σF). The structure contains topologically novel sheets of uranyl square bipyramids, uranyl pentagonal bipyramids, and MoO4 tetrahedra, with composition [(UO2)5(MoO4)8]6−, that are parallel to (−101). H2O groups and 1,4-diazabicyclo [2.2.2]-octane (DABCO) molecules are located in the interlayer, where they provide linkage of the sheets. The structure of 2 [triclinic, , Z=2, a=8.4004(4), b=11.2600(5), c=13.1239(6) Å, α=86.112(1)°, β=86.434(1)°, γ=76.544(1)°, V=1203.14(10) Å] has been solved by direct methods and refined on the basis of F2 for all unique reflections to R1=0.043, which was calculated for 5491 unique observed reflections (|Fo|?4σF). The structure contains topologically novel sheets of uranyl pentagonal bipyramids and MoO4 tetrahedra, with composition [(UO2)(MoO4)2]2−, that are parallel to (110). Ethylenediamine molecules are located in the interlayer, where they provide linkage of the sheets. All known topologies of uranyl molybdate sheets of corner-sharing U and Mo polyhedra can be described by their nodal representations (representations as graphs in which U and Mo polyhedra are given as black and white vertices, respectively). Each topology can be derived from a simple black-and-white graph of six-connected black vertices and three-connected white vertices by deleting some of its segments and white vertices.  相似文献   

12.
The reactivity of bis(dimethylamido) complexes of phenyl- and hydridogallium with ammonia, dimethylamine and 1,1-dimethylhydrazine is described. Synthesis of the starting gallium hydride, [HGa(NMe2)2]2, was achieved in nearly quantitative yield from the reaction of HGaCl2(quinuclidine) with LiNMe2. In neat ammonia or methylamine at room temperature both dimethylamido ligands in [HGa(NMe2)2]2 were substituted by a single equivalent of NH3 or MeNH2 to produce amorphous (HGaNH)n or (HGaNMe)n, respectively. In contrast, the reaction of [PhGa(NMe2)2]2 with neat Me2NNH2, at room temperature consumed two equivalents of the substituted hydrazine to form [PhGa(NHNMe2)2]2 in a 73% yield. Single crystal X-ray crystallographic analyses of [HGa(NMe2)2]2 and [PhGa(NHNMe2)2]2 establish that in the solid state both compounds adopt a cyclic Ga-N-Ga-N structure with a crystallographic center of symmetry located at the center of the ring.  相似文献   

13.
New uranyl vanadates A3(UO2)7(VO4)5O (M=Li (1), Na (2), Ag (3)) have been synthesized by solid-state reaction and their structures determined from single-crystal X-ray diffraction data for 1 and 3. The tetragonal structure results of an alternation of two types of sheets denoted S for 2[UO2(VO4)2]4− and D for 2[(UO2)2(VO4)3]5− built from UO6 square bipyramids and connected through VO4 tetrahedra to 1[U(3)O5-U(4)O5]8− infinite chains of edge-shared U(3)O7 and U(4)O7 pentagonal bipyramids alternatively parallel to a- and b-axis to construct a three-dimensional uranyl vanadate arrangement. It is noticeable that similar [UO5]4− chains are connected only by S-type sheets in A2(UO2)3(VO4)2O and by D-type sheets in A(UO2)4(VO4)3, thus A3(UO2)7(VO4)5O appears as an intergrowth structure between the two previously reported series. The mobility of the monovalent ion in the mutually perpendicular channels created in the three-dimensional arrangement is correlated to the occupation rate of the sites and by the geometry of the different sites occupied by either Na, Ag or Li. Crystallographic data: 293 K, Bruker X8-APEX2 X-ray diffractometer equipped with a 4 K CCD detector, MoKα, λ=0.71073 Å, tetragonal symmetry, space group Pm2, Z=1, full-matrix least-squares refinement on the basis of F2; 1,a=7.2794(9) Å, c=14.514(4) Å, R1=0.021 and wR2=0.048 for 62 parameters with 782 independent reflections with I?2σ(I); 3, a=7.2373(3) Å, c=14.7973(15) Å, R1=0.041 and wR2=0.085 for 60 parameters with 1066 independent reflections with I?2σ(I).  相似文献   

14.
Pentavalent bis(triorganosiloxy)triphenylantimony derivatives, Ph3Sb(OSiR3)2 (R = Me, Ph), were synthesized by reaction of triphenylantimony with trimethyl- or triphenylsilanol in the presence of tert-butylhydroperoxide by the mild reaction conditions (0-5 °C, 2 h). The reaction of triphenylantimony with diethanolamine in the presence of tert-butylhydroperoxide gave the cyclic compound Ph3Sb(OCH2CH2)2NH. The mixture of Ph3SbO and Ph3Sb(OCH2CH2NMe2)2 was obtained by the reaction of triphenylantimony with 2-(N,N-dimethylamino)ethanol in the presence of tert-butylhydroperoxide.  相似文献   

15.
The ternary BaO-TiO2-B2O3 glasses containing a large amount of TiO2 (20-40 mol%) are prepared, and their optical basicities (Λ), the formation, structural features and second-order optical nonlinearities of BaTi(BO3)2 and Ba3Ti3O6(BO3)2 crystals are examined to develop new nonlinear optical materials. It is found that the glasses with high TiO2 contents of 30-40 mol% show large optical basicities of Λ=0.81-0.87, suggesting the high polarizabity of TiOn polyhedra (n=4-6) in the glasses. BaTi(BO3)2 and Ba3Ti3O6(BO3)2 crystals are found to be formed as main crystalline phases in the glasses. It is found that BaTi(BO3)2 crystals tend to orient at the surface of crystallized glasses. The new XRD pattern for the Ba3Ti3O6(BO3)2 phase is proposed through Rietvelt analysis. The second harmonic intensities of crystallized glasses were found to be 0.8 times as large as α-quartz powders, i.e., I2ω(sample)/I2ω(α-quartz)=0.8, for the sample with BaTi(BO3)2 crystals and to be I2ω(sample)/I2ω(α-quartz)=68 for the sample with Ba3Ti3O6(BO3)2 crystals. The Raman scattering spectra for these two crystalline phases are measured for the first time and their structural features are discussed.  相似文献   

16.
A high-yield synthesis of trans-RuCl2(CS)(H2O)(PPh3)2 from RuCl2(PPh3)3 and CS2 is described. The coordinated water molecule is labile, and introduction of CNR (R  p-toyl or p-chlorophenyl) leads to yellow trans-RuCl2(CS)(CNR)(PPh3)2, which isomerises thermally to colourless cis-RuCl2(CS)(CNR)(PPh3)2. Reaction of AgClO4 with cis-RuCl2(CS)(CNR)(PPh3)2 gives [RuCl(CS)(CNR)(H2O)(PPh3)2]+, from which [RuCl(CS)(CO)(CNR)(PPh3)2]+ and [RuCl(CS)(CNR)2(PPh3)2]+ are derived. Reaction of trans-RuCl2(CS)(H2O)(PPh3)2 with sodium formate gives Ru(η2-O2CH)Cl(CS)(PPh3)2, which undergoes decarboxylation in the presence of (PPh3) to give RuHCl(CS)(PPh3)3. Ru(η2-O2CH)H(CS)(PPh3)2 and Ru(η2-O2CMe)-H(CS)(PPh3)2 are also described.  相似文献   

17.
UV irradiation of [Et4N] [V(CO)6] in the presence of the tripod ligands (L) MeC(CH2PPh2)3 (cp3) and P(CH2CH2PPh2)3 (pp3) yields [Et4N] [V(CO)5L], cis-[Et4N] [V(CO)4L] and mer-[Et4N] [V(CO)3L] (where the meridional configuration for L = cp3 is uncertain). Except for [Et4N] [V(CO)5cp3], all these species were isolated. The complexes are characterized by their IR, 31P and 51V NMR spectra.  相似文献   

18.
A re-interpretation and re-evaluation of single-crystal X-ray diffraction data of a previously reported ‘(NH4)2(NH3)[Ni(NH3)2Cl4]’ (J. Solid State Chem. 162 (2001) 254) give a new formula (NH4)2−2z[Ni(NH3)2]z[Ni(NH3)2Cl4] with z=0.152. This new formula results from defects in an idealized ‘(NH4)2[Ni(NH3)2Cl4]’ basic structure, where two adjacent NH4+ cations are replaced by one Ni(NH3)22+ unit. Cl anions from the basic structure complete the coordination sphere of the new Ni2+ to [Ni(NH3)2Cl4]2−.  相似文献   

19.
Synthesis of difunctional N,N′-difluoro perfluoroalkylsulfonamides, CF3SO2NFSO2(CF2)nSO2NFSO2CF3, where n=4, 6 is reported. A related compound with an oxygen linkage CF3SO2NFSO2(CF2)2O(CF2)2SO2NFSO2CF3 has also been prepared. These reagents showed good activity for electrophilic fluorination.  相似文献   

20.
[Pd(C6F5)2(CNR)2] (R = Cy, But, p-MeC6H4 (p-Tol)) react with [PdCl2(NCPh)2] to give [Pd2(μ-Cl)2(C6F5)2(CNR)2]. In refluxing benzene insertion of isocyanide into the C6F5Pd bonds occurs only for R = p-Tol, to give a imidoyl bridged polynuclear complex cis-[Pd2 (μ-Cl)2[μ-C(C6F5) = N(Tol-p)]2n]. This complex reacts with (a) Tl(acac) to give [Pd2{μ-C(C6F5) = N(Tol-p)}2(acac)2]; (b) neutral monodentate ligands to afford dimeric complexes [Pd2{μ-C(C6F5) = N(Tol-p)}2Cl2L2] (L = NMe3, py, 4-Me-py, SC4H8), and (c) isocyanides to give insoluble complexes of the same composition which are thought to be polymeric, [Pd(CNR)Cl{μ-C(C6F5) = N(p-Tol)}]n (R = p-Tol, Me, But). Thermal decomposition of cis-[Pd2 (μ-Cl)2 [μ-C(C6F5) = N( p-Tol)]2n] gives the diazabutadiene species (p-Tol)NC(C6F5)C(C6F5)N(p-Tol) in high yield.  相似文献   

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