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1.
The title compound H3[PMo12O40]· 3C2H6O was prepared and characterized by X-ray crystallography, its i.r. spectrum, cyclic voltammetry and e.s.r. spectra. The anion of the title compound is a Keggin-type heteropoly structure based upon a central PO4 tetrahedron surrounded by 12 MoO6 octahedra arranged in four groups of three edge-shared octahedra Mo3O13. Weak hydrogen bonds exist between the organic solvent molecules and the heteropoly anion. The catalytic activity of the title compound was determined by the synthesis of butyl acetate. The conversion of n-BuOH reached 93.3% and the yield of MeCO2Bu-n was 92.0% when the ratio of MeCO2H to n-BuOH, catalyst amount, reaction time, reaction temperature were 2:1, 0.24% of the reactants (50 mg), 2.0 h and 115 120 °C, respectively. 相似文献
2.
O. Amri S. Abid M. Rzaigui 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):766-777
The crystal structure of a new organic cation cyclohexaphosphate, [4-ClC 6 H 4 CH 2 NH 3 ] 4 Li 2 P 6 O 18 .4H 2 O, is reported. It crystallizes in the triclinic system (space group P-1) with the following unit-cell parameters: a = 9.628(8), b = 12.801(9), c = 19.528(6) Å, α = 78.60(4)°, β = 83.00(5)°, β = 89.98(4)°, Z = 2, and V = 2341(3)Å 3 . The structure has been solved using direct methods and refined by least-squares analysis [R 1 = 0.043, wR 2 = 0.108]. The structure can be described as infinite anionic layers with composition of [Li 2 (P 6 O 18 )(H 2 O) 4 ] 4 ? and parallel to the ac plane. The organic groups are located in the accessible voids. The molecules are stabilized by O─H…O and N─H…O types of intermolecular hydrogen bonds in the unit cell in addition to Van der Waals forces. 相似文献
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The electronic structure of UCoC2, a di-carbide with the C–C units is examined from ab initio with an assessment of the properties of chemical bonding. The energy–volume equation of state shows large anisotropy effects due to C–C alignment along tetragonal c-axis leading to high linear incompressibility. Relevant features of selective bonding of uranium and cobalt with carbon at two different Wyckoff sites and strong C–C interactions are remarkable. The vibrational frequencies for C⋯C stretching modes indicate closer behavior to aliphatic C–C rather than CC double bond. A ferromagnetic ground state is proposed from the calculations. 相似文献
5.
1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m… 相似文献
6.
Helmut Ehrenberg Natalia N. Bramnik Anatoliy Senyshyn Hartmut Fuess 《Solid State Sciences》2009,11(1):18-23
Precise structural data have been determined from a combined Rietveld refinement, based on neutron and X-ray powder diffraction data simultaneously, for the three phases LiCoPO4, LizCoPO4 with a specific intermediate Li-content z = 0.60(10) and CoPO4, which are obtained by electrochemical Li-extraction from LiCoPO4. All three phases are isopointal. Therefore, the transitions between these phases are necessarily of first order, in agreement with their observed coexistence. The same collinear antiferromagnetic structures with magnetic moments nearly parallel to the [010] direction are observed for LiCoPO4 and LizCoPO4, but with a significantly higher Néel temperature of 76 K for the latter compound in comparison with 23 K for LiCoPO4. Olivine-type CoPO4 can only be prepared from LiCoPO4 by delithiation and its physical properties were investigated for the first time. An antiferromagnetic arrangement along the [100] direction is observed for CoPO4 with an additional weak ferromagnetic component along the [001] direction (magnetic space group Pn′m′a and TC = 45 K). The magnetic moment of 3.1(2) μB per Co-ion indicates a mainly high-spin state for Co3+ in the octahedral coordination of CoPO4, which is exceptional and probably the first example in a phosphate. The easy axes and the magnetic exchange interactions between Co-ions change dramatically with the Co2+ ? Co3+ transition. A continuous change of the formal oxidation state of a transition element by electrochemical Li-extraction and a quasi-continuous in situ observation of the resulting magnetic structure by neutron diffraction appear feasible. 相似文献
7.
The title compound (C6N3H18)2Ti4O4(C2O4)7(4H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O4(2H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that 1 crystallizes in the triclinic system, space group Pī with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8)A, α = 96.2915(18), β = 107.998(3), γ = 104.276(4)°, V = 1110.35(14)A3, Z = 2, Dc = 1.807 g/cm3, F(000) = 618, μ = 0.815 mm-1, the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2σ(I). X-ray crystal-structure analysis suggests that compound 1 consists of [Ti4O4(C2O4)7]6- anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)8 by sharing the oxalates as bridging ligands. 相似文献
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《Solid State Sciences》2000,2(3):343-351
The compound NH4(C3H12N3)8{NH4⊃[V2P2BO12]}6·15H2O (1) was synthesized in single-crystal form by interdiffusion at room temperature of aqueous solutions of (NH4)17{NH4⊃[(VO)2BP2O10]6}·nH2O and 1,3-diaminopropane. The compound contains a known cluster anion, but unlike the previously reported examples that were synthesized hydrothermally, shows no disorder. Compound 1 crystallizes in space group Pn with Z=1, a=13.8684(8), b=17.492(1), c=22.500(1) Å, β=102.147° and V=5336.0(5) Å3. The magnetic data show pairwise antiferromagnetic coupling between vanadium(IV) atoms and were fitted by using a modified dimer-exchange model. 相似文献
10.
1 INTRODUCTION The chemistry of organotin(IV) complexes was extensively studied due to their biological activity and coordination chemistry[1~7]. More recently, phar- maceutical properties of alkyltin(IV) complexes with dithiocarbamate ligands have bee… 相似文献
11.
A. V. Gerasimenko I. A. Tkachenko E. B. Merkulov T. F. Antokhina 《Russian Journal of Inorganic Chemistry》2010,55(12):1888-1896
Crystals of MnNbOF5 · 4H2O were studied by X-ray diffraction, differential scanning calorimetry (DSC) and thermogravimetry. DSC showed a phase transition in the temperature range of 282 to 296.3 K. The compound is dehydrated in two stages in the temperature ranges of 65–131.1 and 131.1–190°C, two H2O molecules being removed in each stage. The structure of MnNbOF5 · 4H2O was determined at 153 K (α phase; space group P21/c) and at 297 K (β phase, space group C2/m). The structure of both phases is formed of the octahedral complexes [NbF4(O/F)2/2]0.5? and [Mn(H2O)4(O/F)2/2]0.5+ linked by bridging O and F atoms to infinite chains. The isolated niobium-manganese chains are connected by O-H…F hydrogen bonds. In the α phase, the Nb, O, and F atoms in the trans position relative to O are disordered with respect to the inversion center of the structure. Transition to the β phase is accompanied by splitting of all ligand positions at the Nb and Mn atoms into two equally probable positions. 相似文献
12.
Konarev DV Kuźmin AV Simonov SV Khasanov SS Yudanova EI Lyubovskaya RN 《Dalton transactions (Cambridge, England : 2003)》2011,40(17):4453-4458
New ionic complex {Co(+)(dppe)(2)}·(C(60)˙(-))·(C(6)H(4)Cl(2))(2) (1) was obtained by the reduction of a Co(dppe)Br(2) and C(60) mixture by TDAE in o-dichlorobenzene followed by precipitation of crystals by hexane. Optical and EPR spectra of 1 indicated the formation of C(60)˙(-) radical anions and diamagnetic Co(+)(dppe)(2) cations. The structure of 1 solved at 100(2) K involves chains of C(60)˙(-) arranged along the lattice a-axis with a center-to-center distance of 10.271 ?. The chains are separated by bulky Co(+)(dppe)(2) cations and solvent molecules. All components of 1 are well ordered allowing the distortion of the C(60)˙(-) radical anion to be analyzed. An elongation of the C(60)˙(-) sphere by 0.0254(2) was found. It is essentially smaller than those in the salts (Cp*(2)Ni(+))·(C(60)˙(-))·CS(2) and (PPN(+))(2)·(C(60)(2-)) with greater distortion of the fullerene cage. The calculation of the electronic structure of fullerene by the extended Hückel method showed slight splitting of the C(60) LUMO, due to the distortion, by three levels. Two levels are located 180 and 710 cm(-1) higher than the ground level. The averaged 6-6 and 5-6 bonds in C(60)˙(-) with lengths of 1.397(2) and 1.449(2) ? are close to those determined for the C(60)(2-) dianions in (PPN(+))(2)·(C(60)(2-)), but are slightly longer and shorter, respectively, than the length of these bonds in neutral C(60). 相似文献
13.
《Radiation Physics and Chemistry》1999,53(1):37-46
The mechanism and kinetics of energy transfer from Xe(6s[3/2]1) resonance state (E=8.44 eV) to selected hydrocarbon molecules have been investigated by XeCl(B–X) (λmax=308 nm) fluorescence intensity measurements at stationary conditions in Xe–CCl4–M systems. Steady-state analysis of the fluorescence intensity dependence on the xenon and M pressure at constant CCl4 concentration shows that these process occur in the two- and three-body reactions: Xe(6s[3/2]10)+M→products, Xe(6s[3/2]10+M+Xe→products. The two- and three-body rate constants for these reactions have been found (see Table 1Table 1. Experimental parameters of Eq. (8)found by least square method in Xe–CCl4–C2H2 and Xe–CCl4–C2H4 systems for chosen xenon pressures in the range 25–150 Torr. Linear correlation coefficients (R) are also shown
P(Xe) (Torr) | C2H4 | C2H2 | ||||
---|---|---|---|---|---|---|
Empty Cell | a | b×1016 cm3/molec. | R | a | b×1016 cm3/molec. | R |
25 | 0.92 | 3.26 | 0.98 | 1.00 | 2.78 | 0.95 |
40 | 0.86 | 3.29 | 0.97 | 1.00 | 2.91 | 0.98 |
50 | 0.87 | 3.33 | 0.97 | 0.99 | 3.05 | 0.98 |
60 | 0.85 | 3.33 | 0.97 | 1.02 | 2.99 | 0.98 |
75 | 0.86 | 3.39 | 0.97 | 1.03 | 2.95 | 0.98 |
90 | 0.92 | 3.30 | 0.97 | 1.03 | 2.85 | 0.98 |
100 | 0.92 | 3.21 | 0.98 | 1.0 | 2.77 | 0.98 |
110 | 0.88 | 3.19 | 0.96 | 1.02 | 2.71 | 0.99 |
125 | 0.86 | 3.12 | 0.95 | — | — | — |
140 | 0.92 | 2.90 | 0.95 | — | — | — |
150 | 0.95 | 2.77 | 0.94 | — | — | — |