The Far Infrared Spectra and X-Ray Powder Diffraction Patterns of the Structure I Hydrates of Cyclopropane and Ethylene Oxide at 100 °K

1975 ◽  
Vol 53 (1) ◽  
pp. 71-75 ◽  
Author(s):  
John E. Bertie ◽  
Frances E. Bates ◽  
David K. Hendricksen

This paper presents the far-infrared spectrum and X-ray powder diffraction pattern of the structure I hydrate of cyclopropane at 100 °K, and the powder diffraction pattern of the isostructural ethylene oxide hydrate at 100 °K. Between 360 and 100 cm−1 the absorption by cyclopropane hydrate is essentially identical to that by ethylene oxide hydrate, but is shifted to low frequency by about 2%. This shift is undoubtedly related to the hydrogen bonds being slightly longer in cyclopropane hydrate, whose cubic lattice parameter is 11.98 ± 0.02 Å compared to 11.89 ± 0.02 Å for ethylene oxide hydrate, both at 110 ± 20 °K. The absorption by cyclopropane hydrate below 100 cm−1 decreases rapidly with decreasing frequency; this confirms that the absorption plateau observed for ethylene oxide hydrate between 100 and about 50 cm−1 is due to primarily rotational vibrations of ethylene oxide. A recent statement, that the orientational disorder of the water molecules need not be invoked to explain the far infrared spectrum of ice 1 h, is disputed.

2012 ◽  
Vol 27 (4) ◽  
pp. 256-262 ◽  
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
H. Wu ◽  
M. Suchomel

M2(dhtp)·nH2O (M = Mn, Co, Ni, Zn; dhtp = 2,5-dihydroxyterephthalate), known as MOF74, is a family of excellent sorbent materials for CO2 that contains coordinatively unsaturated metal sites and a honeycomb-like structure featuring a broad one-dimensional channel. This paper describes the structural feature and provides reference X-ray powder diffraction patterns of these four isostructural compounds. The structures were determined using synchrotron diffraction data obtained at beam line 11-BM at the Advanced Photon Source (APS) in the Argonne National Laboratory. The samples were confirmed to be hexagonal R 3 (No. 148). From M = Mn, Co, Ni, to Zn, the lattice parameter a of MOF74 ranges from 26.131 73(4) Å to 26.5738(2) Å, c from 6.651 97(5) to 6.808 83(8) Å, and V ranges from 3948.08 Å3 to 4163.99 Å3, respectively. The four reference X-ray powder diffraction patterns have been submitted for inclusion in the Powder Diffraction File (PDF).


1987 ◽  
Vol 2 (3) ◽  
pp. 176-179 ◽  
Author(s):  
G. Wilson ◽  
F. P. Glasser

AbstractA systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.


1972 ◽  
Vol 50 (21) ◽  
pp. 3443-3449 ◽  
Author(s):  
J. E. Bertie ◽  
D. A. Othen

The infrared spectra of authenticated samples of ethylene oxide hydrate and deuterate at 100 °K have been measured between 360 and 20 cm−1. The spectra confirm that the water molecules are orientationally-disordered and reorient slowly compared to far-infrared frequencies. An empirical correlation is suggested between the frequencies of strong absorption and the number of non-equivalent hydrogen bonds, their length and distribution. The contribution to the spectrum by the ethylene oxide intermolecular vibrations is discussed.


1999 ◽  
Vol 14 (4) ◽  
pp. 276-279
Author(s):  
Wiesław Łasocha ◽  
Wiesław Surga ◽  
Alicja Rafalska-Łasocha

The X-ray powder diffraction data of polycrystalline fibrillar zinc trimolybdates ZnMo3O10·3.75H2O, ZnMo3O10·5H2O, and ZnMo3O10·10H2O, are reported. An uncommon diffraction pattern was recorded in the case of the “wet fibers” of ZnMo3O10·10H2O, which could be indexed assuming a model of parallel fibers with translation disorder along the fiber axis. The powder diffraction patterns, lattice parameters, space groups, and other data describing these compounds are presented in this paper.© 1999 International Centre for Diffraction Data.


1989 ◽  
Vol 22 (6) ◽  
pp. 622-623 ◽  
Author(s):  
B. Pałosz ◽  
E. Salje

Structural transformations between polytypes of a given material are expected to lead to lattice relaxations. Powder X-ray diffraction of basic AX 2 polytypes of CdI2, PbI2, SnS2 and SnSe2 showed these relaxations for the repetition unit along the stacking axis, conventionally the c axis. No variation of the lattice parameters were detected in the basal plane (001), except for CdI2 where small variations occur also for the a lattice parameter. The tensor of the spontaneous strain has its maximum component e 3 ≲ 12 × 10−4 for SnS2. The powder diffraction pattern and lattice parameters of the phases of CdI2 (2H, 12R, 4H), PbI2 (2H, 12R), SnS2 (2H, 18R, 4H) and SnSe2 (2H, 18R) are given. JCPDS Diffraction File Nos. are: 40-1468 for CdI2-12H; 40–1469 for CdI2-2H; 40-1466 for SnS2-18R, 40–1467 for SnS2-2H; 40–1465 for SnSe2-18R. The other polytypes studied in this paper have data in earlier sets of the PDF.


2013 ◽  
Vol 29 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Ana Palčić ◽  
Ivan Halasz ◽  
Josip Bronić

The crystal structure of copper(ii) citrate monohydrate (C6H4O7Cu2·H2O) has been solved from a mixture powder diffraction pattern. Approach to indexing, structure solution and Rietveld refinement of multiphase diffraction patterns is discussed. Rietveld refinement is carried out employing free-atom refinement and rigid body refinement.


1983 ◽  
Vol 47 (344) ◽  
pp. 391-392 ◽  
Author(s):  
K. A. Butt ◽  
K. Mahmood

AbstractMunirite was found in the sandstones of Siwaliks formation of mid-Miocene to Pleistocene age. It occurs as small globular clusters of acicular crystals (2 to 3 mm long). Analysis gave V2O5 67.46, N2O 22.91, and H2O 10.26%. The X-ray powder diffraction pattern shows remarkable similarity to a synthetic compound NaVO3 · 1.9H2O (Lukacs and Strausievici, 1962).


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