Raman spectroscopic determination of phase evolutions in LiAlxCo1−xO2 battery materials

2001 ◽  
Vol 16 (1) ◽  
pp. 1-4 ◽  
Author(s):  
P. S. Dobal ◽  
R. S. Katiyar ◽  
M. S. Tomar ◽  
A. Hidalgo

Superior battery materials LiAlxCo1−xO2 (x = 0.0, 0.1, 0.3, 0.5, and 0.7) were synthesized using a solution-based route at various sintering temperatures (450–800 °C). In this communication, we report on the use of Raman spectroscopy to study effect of composition and sintering temperature on the resulting material. The phase evolutions in LiAlxCo1−xO2 compositions were studied using micro-Raman spectroscopy and a phase diagram is proposed based on the observations. For less Al content, the low-temperature phases of LiAlxCo1−xO2 showed Raman spectra corresponding to a monoclinic (space group C2/m) structure, while a low-temperature spinel (space group Fd3m) phase was observed for 50% or more Al in these compounds. All these compositions exhibited a layered hexagonal (space group R3m) structure when sintered above 700 °C. Raman spectra also revealed residual Co3O4 in the low-temperature forms of LiCoO2 and LiA10.01Co0.9O2.

1999 ◽  
Vol 54 (8) ◽  
pp. 1009-1014 ◽  
Author(s):  
L. Homolya ◽  
W. Preetz

The crystal structures of cis-(n-Bu4N)2[ReBr4(NCS)(SCN)] (1) (monoclinic, space group P21/n, a = 11.203(3), b = 11.738(5), c = 35.218(7) Å, β = 93.434(4)°, Z = 4), trans-(n-Bu4N)2[ReBr4(NCS)(SCN)] (2) (monoclinic, space group P21/n, a = 11.644(7), b = 13.695(3), c = 29.028(8) Å, β = 95.96(4)° Z = 4) and trans-(n-Bu4N)2[ReBr4(NCSe)(SeCN)] (3) (monoclinic, space group P21/n, a = 11.894(2), b = 13.737(2), c = 28.869(7) Å, β = 96.98(10)° Z = 4) have been determined by single crystal X-ray diffraction analysis. Based on these molecular parameters the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts have been assigned by normal coordinate analysis. The valence force constants are fd(ReN) = 1.70 (1), 1.75 (2) and 1.75 (3), fd(ReS) = 1.32 (1) and 1.37 (2) and fd(ReSe) = 1.20 mdyn/Å (3).


2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.


1978 ◽  
Vol 56 (17) ◽  
pp. 2253-2258 ◽  
Author(s):  
Morley Brownstein ◽  
Ronald J Gillespie ◽  
John P. Krasznai

The reactions of IOF5 with SbF5 and with AsF5 have been investigated at low temperature by 19F nmr and Raman spectroscopy. It was found that SbF5 forms labile 1:1 and 2:1 complexes whereas AsF5 forms only a 1:1 complex. The IOF5 is bound through its oxygen atom to the Lewis acids AsF5, SbF5, or (SbF5)2.


1985 ◽  
Vol 40 (7) ◽  
pp. 872-877 ◽  
Author(s):  
W. Kolondra ◽  
W. Schwarz ◽  
J. Weidlein

Abstract Unexpectedly the reaction of SbCl3 with Na(N{SiMe3}2) in a 1:3 molar ratio forms MeSb(N{SiMe3}2)2, I, (Me = CH3) and other trimethylsilyl compounds. The colourless and liquid methylstibane derivative I is monomeric in solution and forms MeSbCl2(N{SiMe3}2)2 (II) on reaction with SO2Cl2. Both new compounds have been characterized by analyses, NMR, IR and Raman spectra. The X-ray structure determination for II shows the monoclinic space group P21/C with 4 monomeric units per cell. The structure was refined to an R-value of 0,052.


1996 ◽  
Vol 74 (9) ◽  
pp. 1671-1681 ◽  
Author(s):  
Jack Passmore ◽  
Paul D. Boyle ◽  
Gabriele Schatte ◽  
Todd Way ◽  
T. Stanley Cameron

Alternative and, in some cases, improved syntheses of the salts MX3(As/Sb)F6 (M = S, Se) and SCl3(SbCl6/AlCl4) are described. In addition, the synthesis of SeCl3SbF6 is reported. The compounds were characterized by FT–Raman spectroscopy and the X-ray crystal structures of SeCl3AsF6 (also 77Se NMR) and a new phase of SBr3SbF6 were determined. Crystals of SeCl3AsF6 and SBr3SbF6 are monoclinic, space group P21/c with [values for SBr3SbF6 in brackets] a = 7.678(1) [8.137(1)] Å, b = 9.380(3) [9.583(2)] Å, c = 11.920(3) [12.447(2)] Å, β = 98.19(2)° [97.36(1)]°, V = 849.72(3) [962.6(3)] Å3,z = 4, Dx = 2.925 [3.502] Mg m−3, R = 0.0525 [0.055], and Rw = 0.0554 [0.060] for 1151 [1472] observed reflections. Key words: MX3+ salts, FT–Raman spectroscopy, X-ray crystal structures of SeCl3AsF6, SBr3SbF6, and preparation of SeCl3SbF6.


1998 ◽  
Vol 53 (12) ◽  
pp. 1528-1530 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones

Abstract Benzo-18 -crown-6 -Acetonitrile (1/2), Crystal Structure Single crystals of the title complex resulted fortuitously during an attempt to co-crystallise MeN(SO2Me)2 with benzo-18-crown-6 from an MeCN solution at -30 °C. The crystal structure has been determined via data collection at -100 °C (monoclinic, space group P21/n, Z = 4). The nitrile molecules are located with their me­ thyl groups above and below the plane of the 18-membered crown ring, the Me hydrogen atoms being rotationally disordered about the MeCN axes; C(methyl)···O(crown) distances range from 309.4(3) to 384.9(3) pm.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Konstantis F. Konidaris ◽  
Rigini Papi ◽  
Eugenia Katsoulakou ◽  
Catherine P. Raptopoulou ◽  
Dimitrios A. Kyriakidis ◽  
...  

The employment of 3-pyridine aldoxime, (3-py)CHNOH, in ZnIIchemistry has afforded two novel compounds: [Zn(acac)2{(3-py)CHNOH}]⋅H2O(1⋅H2O) [where acac-is the pentane-2,4-dionato(-1) ion] and [Zn2(O2CMe)4{(3-py)CHNOH}2] (2). Complex1⋅H2Ocrystallizes in the monoclinic space groupP21/n. The ZnIIion is five-coordinated, surrounded by four oxygen atoms of two acac-moieties and by the pyridyl nitrogen atom of the (3-py)CHNOH ligand. Molecules of1interact with the water lattice molecules forming a 2D hydrogen-bonding network. Complex2crystallizes in the triclinicP-1space group and displays a dinuclear paddle-wheel structure. Each ZnIIexhibits a perfect square pyramidal geometry, with four carboxylate oxygen atoms at the basal plane and the pyridyl nitrogen of one monodentate (3-py)CHNOH ligand at the apex. DNA mobility shift assays were performed for the determination of thein vitroeffect of both complexes on the integrity and the electrophoretic mobility of pDNA.


2001 ◽  
Vol 57 (6) ◽  
pp. 791-799 ◽  
Author(s):  
Menahem Kaftory ◽  
Mark Botoshansky ◽  
Moshe Kapon ◽  
Vitaly Shteiman

4,6-Dimethoxy-3-methyldihydrotriazine-2-one (1) undergoes a single-crystal to single-crystal reversible phase transformation at 319 K. The low-temperature phase crystallizes in monoclinic space group P21/n with two crystallographically independent molecules in the asymmetric unit. The high-temperature phase is obtained by heating a single crystal of the low-temperature phase. This phase is orthorhombic, space group Pnma, with the molecules occupying a crystallographic mirror plane. The enthalpy of the transformation is 1.34 kJ mol−1. The small energy difference between the two phases and the minimal atomic movement facilitate the single-crystal to single-crystal reversible phase transformation with no destruction of the crystal lattice. On further heating, the high-temperature phase undergoes methyl rearrangement in the solid state. 2,4,6-Trimethoxy-1,3,5-triazine (3), on the other hand, undergoes an irreversible phase transformation from single-crystal to polycrystalline material at 340 K with an enthalpy of 3.9 kJ mol−1; upon further heating it melts and methyl rearrangement takes place.


1989 ◽  
Vol 44 (2) ◽  
pp. 121-126 ◽  
Author(s):  
W. Preetz ◽  
J. Thesing

Abstract The low temperature Raman spectra (10 K) of Cs2B6H6 and its 11B and 10B enriched derivatives prepared for the first time show well resolved signals o f the B6-cage vibrations υ1 (A1g), υ3(Eg) and υ9(T2g) for all isotopomers 11B10B6-nH62 -, n = 0-6. The intensities o f the sharp peaks correlate exactly with the statistical abundance ratio. W hereas the frequency decreases by nearly equidistant steps of 7 cm-1 with increasing n values, the geometric isomers for n = 2, 3 and 4 are separated by only about 2 cm-1. The band assignments are verified by Teller-Redlich calculations.


1999 ◽  
Vol 52 (5) ◽  
pp. 403 ◽  
Author(s):  
Zouhair Asfari ◽  
Jack M. Harrowfield ◽  
Pierre Thuéry ◽  
Martine Nierlich ◽  
Jacques E. Vicens

An insoluble material formed in attempts to extract the copper(II) complex of (R,S)-5,5,7,12,12,14- hexamethyl-1,4,8,11-tetraazacyclotetradecane with the tetraanion of tetrakis(carboxymethyl) p-t-butylcalix[4]arene recrystallizes from pyridine with the composition [Cu(C16H36N4)] [Na2(C52H60O12)].2C5H5N.4·5H2O. The crystals are monoclinic, space group P 21/c (C52h, No. 14); a 26·8524(8), b 12·8151(2), c 25·6525(8) Å; β 115·356(1)°. The structure was refined on F2 (11379 reflections, 955 parameters), giving conventional R1 0·057 (wR2 0·118). The calixarene encapsulates two sodium ions and has only tenuous connection to the copper/macrocycle complex through axial coordination of one carboxylate oxygen.


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