Superlattice formation in the lithiated vanadium oxide phases Li0.67V6O13 and LiV6O13

2001 ◽  
Vol 57 (6) ◽  
pp. 759-765 ◽  
Author(s):  
Helen Björk ◽  
Sven Lidin ◽  
Torbjörn Gustafsson ◽  
John O. Thomas

Two new lithiated phases of V6O13 were formed by carefully tuning the temperature of electrochemical lithiation in a `coffee-bag' type Li-ion battery at 2.78 V versus Li/Li+. These were studied by single-crystal X-ray diffraction. A phase with the composition Li2/3V6O13 was obtained at 308 K with a unit cell three times the volume of the original V6O13 cell. A single crystal discharged at ambient temperature was shown to be LiV6O13 and twice the unit-cell volume of the original V6O13 cell. On lithiation, the structures retain their basic V6O13 structure of alternating single and double layers of VO6 octahedra. The lithium ions occupy chemically equivalent sites, where they coordinate fivefold to O atoms, and associate with the single layers of VO6 octahedra. The insertion of lithium causes a significant elongation of one of the V—O bonds in each structure, which expands from 1.65 to 1.89 Å; this is due to the charge reduction of a specific V atom.

2007 ◽  
Vol 71 (5) ◽  
pp. 579-585 ◽  
Author(s):  
A. Guastoni ◽  
F. Nestola ◽  
G. Mazzoleni ◽  
P. Vignola

AbstractMn-rich graftonite, (Ca,Mn2+)(Fe2+,Mn2+)2(PO4)2, ferrisicklerite, Li1–x(Fe3+,Mn2+)PO4, manganoan apatite, (Ca,Mn2+,Fe2+Mg)(PO4)3Cl, staně kite, Fe3+Mn2+O(PO4) and Mn-rich vivianite, (Fe2+)3(PO4)2·8H2O, occurring in a granitic pegmatite at Soè Valley (central Alps, Italy) were characterized by powder and single-crystal X-ray diffraction (XRD) and electron microprobe analyses. Geochemically, the Mn-rich graftonite phases are poorly evolved Fe/Mn-phosphates of rare-earth elements-lithium (REE-Li) granitic pegmatites. The assemblage Mn-rich graftonite + ferrisicklerite + staněkite has rarely beendocumen ted in pegmatites. Inthe Soè Valley pegmatite, ferrisicklerite forms exsolution lamellae with Mn-rich graftonite associated with manganoan apatite and staněkite. Graftonite is associated with Mn-rich vivianite. Powder and single-crystal XRD data indicate that the unit-cell volume of graftonite increases as a function of Mn2+content. Staněkite shows a distinctly smaller unit-cell volume with respect to previously reported staněkites, probably due to reduced Mn2+. Vivianite with significant Mn2+has a unit-cell volume similar to nearly Mn-free vivianite. The formation of Mn-rich graftonite and manganoan apatite is related to destabilization of Mn-rich almandine and biotite during pegmatite formation. Ferrisicklerite forms exsolution lamellae along the 010 cleavage planes of Mn-rich graftonite, whereas staněkite forms by alterationof ferrisicklerite and Mn-rich vivianite due to circulation of late-stage hydrothermal fluids.


1995 ◽  
Vol 50 (4) ◽  
pp. 699-701 ◽  
Author(s):  
Norbert W. Mitzel ◽  
Jürgen Riede ◽  
Klaus Angermaier ◽  
Hubert Schmidbaur

The solid-state structure of N,N-dibenzylhydroxylamine (1) has been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 21/n with four formula units in the unit cell. N,N-dibenzylhydroxylamine dimerizes to give N2O2H2 sixmembered rings as a result of the formation of two hydrogen bonds O - H ··· N in the solid state.


1996 ◽  
Vol 52 (1) ◽  
pp. 140-144 ◽  
Author(s):  
H. van Koningsveld ◽  
J. C. Jansen ◽  
H. van Bekkum

The crystal structure of a high-loaded complex of H-ZSM-5 with eight molecules of p-dichlorobenzene per unit cell has been solved by single-crystal X-ray diffraction. The orthorhombic space group P212121 with a = 20.102 (6), b = 19.797 (9), c = 13.436 (3) Å and V = 5347 (3) Å3 has four Si23.92Al0.08O48.2C6H4Cl2 units per unit cell. Dx = 2.164 Mg m−3, λ(MoKα) = 0.71073 Å and μ(Mo Kα) = 0.876 mm−1. The final R(wR) = 0.046 (0.039), w = 1/σ 2(F), for 6090 observed reflections with I > 1.0σ(I) measured at 293 K. The straight channel parallel to [010] is slightly corrugated. The elliptical cross sections have limiting apertures of 6.0 × 4.9 Å (r oxygen = 1.35 Å). The sinusoidal channel parallel to [100] is elliptical with major and minor axes of 6.1 × 4.8 Å, respectively. One of the two independent p-dichlorobenzene molecule lies at the intersection of the straight and sinusoidal channels with its long molecular axis almost parallel to (100) and deviating ~8° from [010]. The second p-dichlorobenzene molecule is in the sinusoidal channel. Its long molecular axis deviates almost 7° from [100] and is practically parallel to (010). The structural aspects are in all details comparable to those in the high-loaded H-ZSM-5/p-xylene complex [van Koningsveld, Tuinstra, van Bekkum & Jansen (1989). Acta Cryst. B45, 423–431] , except for the main interaction forces between the p-dichlorobenzene molecules at the channel intersection.


1996 ◽  
Vol 63 (1) ◽  
pp. 41-45 ◽  
Author(s):  
A.H. Whitehead ◽  
K. Edström ◽  
N. Rao ◽  
J.R. Owen

1988 ◽  
Vol 43 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Peter Stolz

(Ph4P)2Mn2Br6 (1) and (Ph3PCH2Ph)2Mn2I6 (2) were prepared from the reaction of manganese dihalide with the corresponding phosphonium halide in CH2Cl2.The structures of 1 and 2 were determined from single crystal X-ray diffraction data.Both compounds crystallize in the triclinic space group P 1 with one formula unit per unit cell.1:a = 998.1(1), b = 1005.7(1), c = 1313.3(2) pm, α = 108.51(1), β = 94.25(1), γ = 100.36(1)°.2: a = 1058.6(2), b = 1236.3(2), c = 1248.4(3) pm, α = 63.53(1), β = 74.15(1), γ = 74.65(1)°.The structures of 1 and 2 exhibit discrete, dimeric anions formed by the fusion of two identical tetrahedral-like units with a common halogen-halogen edge. The mean Mn-Hal bond lengths were found to be 251.8 pm (Mn-Br) and 272.2 pm (Mn-I). The difference between the bridging and terminal Mn-Hal bond lengths is about 12-13 pm in both compounds


1994 ◽  
Vol 49 (12) ◽  
pp. 1654-1658 ◽  
Author(s):  
Markus Wieber ◽  
Stefan Lang ◽  
Stefan Rohse ◽  
Ralph Habersack ◽  
Christian Burschka

The synthesis of triphenyltelluroniumsulfide (Ph3TeS)4 is described together with a NMR-spectroscopic characterization. The structure of the title compound was determined by single crystal X-ray diffraction. Crystals of triphenyltelluroniumsulfide are triclinic (space group P1) with the cell parameters a = 1178.0(3) pm. b = 1295.8(6) pm. c = 1298.7(4) pm, α = 77.67(3)°, β = 82.18(2)°, γ = 66.00(2)° (V = 1766(1) × 106 pm3) and Z = 2. The compound appears to form a step-like structure of two [Ph3TeS]2 units and crystallizes with two molecules of CH2Cl2 per unit cell.


2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g−1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g−1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.


1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.


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