ChemInform Abstract: 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 6 (17) ◽  
Author(s):  
JOHN E. BERTIE ◽  
FRANCES E. BATES ◽  
DAVID K. HENDRICKSEN
Keyword(s):  
Ethylene Oxide ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Far Infrared ◽  
X Ray ◽  
Diffraction Patterns ◽  
Far Infrared Spectra

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
Keyword(s):  
Infrared Spectrum ◽  
Ethylene Oxide ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Low Frequency ◽  
Far Infrared ◽  
Lattice Parameter ◽  
X Ray ◽  
Oxide Hydrate ◽  
Diffraction Patterns

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.

The thermal behaviour of an Fe-rich illite

Clay Minerals ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 45-52 ◽  
Author(s):  
E. Murad ◽  
U. Wagner
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Phase Changes ◽  
X Ray ◽  
Structural Breakdown ◽  
Characteristic Features ◽  
Diffraction Patterns ◽  
Good Agreement ◽  
Subsequent Disappearance

AbstractThe phase changes that took place upon heating an Fe-rich illite (OECD #5) to 1300°C in an oxidizing atmosphere were studied by a variety of mineralogical techniques. Infrared spectra, showing the stepwise dehydroxylation of the illite, showed good agreement with variations in sample colour and Mössbauer spectra. Dehydroxylation did not lead to noticeable variations in X-ray powder diffraction patterns until the structural breakdown of illite and formation of new phases at about 900°C Mössbauer spectroscopy proved to be very sensitive to all changes induced by heating, showing the disappearance of Fe2+ at 250°C, the gradual dehydroxylation between about 350 and 900°C, and characteristic features of the products formed at higher temperatures, e.g. the formation of hematite as the illite structure breaks down and the subsequent disappearance of hematite due to the incorporation of Fe in glass above 1200°C. The formation of hematite in clusters large enough to order magnetically at room temperature was first observed in the sample heated to 900°C, whereas at 4.2 K, significant proportions of a magnetically ordered phase could already be identified in the sample heated to 650°C.

Physico-Chemical Characterization of Some 5,5-Disubstituted-1,3-Dixanthyl Barbituric Acids

1967 ◽  
Vol 21 (4) ◽  
pp. 225-231 ◽  
Author(s):  
B. C. Flann ◽  
J. A. R. Cloutier
Keyword(s):  
Experimental Data ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Chemical Characterization ◽  
Melting Points ◽  
X Ray ◽  
Physico Chemical ◽  
Diffraction Patterns ◽  
Derivatives Of

The dixanthyl derivatives of 21 clinically important barbituric acids have been prepared. Melting points, infrared spectra, and x-ray powder-diffraction patterns of the purified compounds are presented. Infrared evidence is used to discuss the position of the linkage between the xanthyl and barbiturate portions of the derivatives. The experimental data should prove of particular value for the microchemical identification of barbiturates.

scholarly journals Infrared Spectra of the Clathrate Hydrates

1978 ◽  
Vol 21 (85) ◽  
pp. 694-696
Author(s):  
D. A. Othen ◽  
P. G. Wright ◽  
F. E. Bates ◽  
D. K. Hendricksen ◽  
S. M. Jacobs ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Infrared Spectra ◽  
Guest Molecule ◽  
Far Infrared ◽  
Water Molecules ◽  
Guest Molecules ◽  
Oxide Structure ◽  
Trimethylene Oxide ◽  
Ray Methods ◽  
Far Infrared Spectra

AbstractDetailed mid- and far-infrared spectra have been recorded for authenticated samples of several clathrate hydrates with the two main structures, I and II, at temperatures between 150 and 4 K. The systems are complicated, yet a detailed analysis of the many interesting spectral features is required before reliable, detailed information can be obtained. Consequently only rather general conclusions can be drawn at present.The mid-infrared spectra have been recorded for the structure I hydrates and deuterates of ethylene oxide, trimethylene oxide, and cyclopropane, and the structure II hydrate and deuterate of trimethylene oxide, all at 100 K. The OD stretching vibrations of isolated HDO molecules, vOD (HDO), and of the fully deuterated forms, vOD(D2O), have also been recorded for cyclopropane and trimethylene oxide structure I hydrates at 40 K, and the absorption by the guest molecules has been studied for all of the structure I hydrates at temperatures down to 40 K.The absorption by the water molecules at 100 K is similar to that in ice, with frequencies that vary in the expected way with the lattice parameter and, hence, the hydrogen bond lengths. The shapes of the vOH(H2O)vOD(D2O), and vR(D2O) bands are essentially the same for structures I and II, while the vOD(D2O) band varies only slightly and depends more on the guest molecule than on the structure. The water absorption changed only slightly when the samples were cooled from 100 to 40 K.The vOD(HDO) bands provide clear evidence that the distribution of hydrogen bond lengths in cyclopropane hydrate differs from those in ethylene oxide and trimethylene oxide structure I hydrates, even though powder X-ray methods indicate that the three hydrates are isostructural. The difference is attributed to an interaction between the hydrogen bonds and the dipole moment of the guest which is too irregular to be sensed by powder X-ray methods.Some absorption bands of the guest molecules are visible in the spectra of structure I hydrates and, as expected, fewer are visible in the spectra of structure II hydrates, which have a higher water-to-guest ratio. For both structures more guest bands are visible in the spectra of deuterates since the D2O absorption is weaker than that of H2O. The guest bands are single in most cases, with half-widths of 1 to 5 cm-1 for ethylene oxide and cyclopropane and 5 to 15 cm-1 for trimethylene oxide in its deuterates of both structures. One band of ethylene oxide at 100 K and below is a doublet, and one degenerate and one non-degenerate vibration of cyclopropane yields a doublet at 40 K. This must mean that there are two non-equivalent positions for the guest molecule in the tetrakaidecahedral cage of the structure I hydrate at these temperatures.Far infrared spectra have been recorded of the structure I hydrates of ethylene oxide, cyclopropane, trimethylene oxide, and xenon, and of the structure II hydrates of trimethylene oxide, cyclopropane, tetrahydrofuran, cyclobutanone, and 1,3-dioxolane, all at 4.3 K. The spectra of the hydrates and corresponding deuterates have enabled the absorption by the rotational vibrations of the guest molecules in the cage to be identified. The absorption above 100 cm-1 by the translational vibrations of the water molecules is significantly different for the two structures, but is rather insensitive to the guest molecule within one structure.A careful search was made for evidence of the transition in trimethylene oxide structure I hydrate at which the guest molecules partly order, that was detected by Davidson from dielectric studies. No spectral changes due to the transition were detected.Papers describing this work have been published in Canadian. Journal of Chemistry, Vol. 51, No. 8, 1973, p. 1159-68; Vol. 53, No. 1, 1975, p. 71-75; Vol. 55, No. 10, 1977, p. 1777-85. A further paper is accepted for publication in Journal of Chemical Physics and others arc in preparation.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LXX Synthesis, Spectroscopy and Structural Systematics of 1 : 2 Binuclear Adducts of Copper(I) Halides with Triphenylstibine, [(Ph3Sb)2Cu(-X)2Cu(SbPh3)2], X = Cl, Br, I

1997 ◽  
Vol 50 (6) ◽  
pp. 621 ◽  
Author(s):  
Robert D. Hart ◽  
Graham A. Bowmaker ◽  
Eban N. de Silva ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Infrared Spectra ◽  
Related Species ◽  
Far Infrared ◽  
Lewis Base ◽  
The Other ◽  
X Ray ◽  
Structure Determinations ◽  
Far Infrared Spectra

Crystallization of 1 : 2 mixtures of the copper(I) halides CuX, X = Cl, Br, I, with triphenylstibine from acetonitrile yields adducts of 1 : 2 CuX/SbPh3 stoichiometry, confirmed by single-crystal X-ray structure determinations. The three complexes are isomorphous, monoclinic, P 21/c, a ≈ 24·3, b ≈ 14·2, c ≈ 20 Å, β 110°, Z = 4 dimers; conventional R on F were 0·047, 0·044 and 0·045 for No 11247, 4673 and 10418 independent ‘observe’ (I > 3σ(I)) reflections respectively. The complexes, also isomorphous with some related species, e.g. 1 : 2 AgBr,I/AsPh3, are dimers: [(Ph3Sb)2Cu(µ-X)2Cu(SbPh3)2]. The chloride is also recorded as a chloroform disolvate, isomorphous with its arsine analogue, being monoclinic, C 2/c, a 21·486(9), b 17· 925(9), c 19·972(7) Å, β 91·31(3)°, Z = 4 dimers, R 0·057 for No 3756. The far-infrared spectra of [(Ph3Sb)2Cu(µ-X)2Cu(SbPh3)2] (X = Br, I) showed no clear v(CuX) bands, in contrast to the situation reported previously for the corresponding Ph3As compounds. A possible v(CuCl) band is observed in the X = Cl complex at 219 cm-1 , but this occurs in a region where there is also significant absorption in the other two compounds. The absence of strong v(CuX) bands in these complexes is consistent with the situation observed previously for the 3 : 1 compounds [(Ph3Sb)3CuX].

Studies of the phosphorodiamidates of alkali metals

1969 ◽  
Vol 47 (14) ◽  
pp. 2613-2617 ◽  
Author(s):  
Y. N. Sadana
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Alkali Metals ◽  
Potassium Salts ◽  
X Ray ◽  
Diffraction Patterns ◽  
Sodium And Potassium

Phosphorodiamidates of lithium, rubidium, and cesium have been prepared and characterized. The infrared spectra and the X-ray powder diffraction patterns of these and the previously known sodium and potassium salts have been recorded and discussed.

Synthetic, Structural and Vibrational Spectroscopic Studies in Bismuth(III) Halide/N,N′-Aromatic Bidentate Base Systems. V Bismuth(III) Halide/N,N′-Bidentate Ligand (1 : 2) Systems

1998 ◽  
Vol 51 (4) ◽  
pp. 331 ◽  
Author(s):  
Graham A. Bowmaker ◽  
Frances M. M. Hannaway ◽  
Peter C. Junk ◽  
Aaron M. Lee ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Single Crystal ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Far Infrared ◽  
Spectroscopic Studies ◽  
Bidentate Ligand ◽  
X Ray ◽  
B 31 ◽  
Far Infrared Spectra

Syntheses and room-temperature single-crystal X-ray determinations are recorded for a number of adducts of BiX3/N,N′-bidentate 1 : 2 stoichiometry (N,N′-bidentate = 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)). BiX3/bpy (1 : 2), X = Br, I, are isomorphous, monoclinic, P21/c, a ≈ 7·5, b ≈ 31, c ≈ 10·3 Å, β ≈ 113°, Z = 4; conventional R on |F| were 0·058, 0·055 for No 1744, 2068 independent ‘observed’ (I > 3σ(I)) reflections. BiCl3/phen (1 : 2) is monoclinic, P21/C, a 9·675(3), b 31·845(7), c 7·756(2) Å, β 109·94(2), Z = 4, R 0·071 for No 2537, while BiBr3/phen (1 : 2), also monoclinic, P21/c, has a 17·590(5), b 8·812(2), c 17·537(7) Å, β 117·58(3)°, Z = 4; R 0·083 for No 890. BiX3/phen (1 : 2).S, X/S = Br/MeCN, I/CH2Cl2, are isomorphous, orthorhombic, Pna21, a ≈ 20·7, b ≈ 14·2, c ≈ 8·9 Å, Z = 4, R 0·060, 0·046 for No 1553, 2423 respectively. All complexes are mononuclear with seven-coordinate (N2)2BiX3 bismuth environments. Bands in the far-infrared spectra due to the v(BiX) vibrations in [(phen)2BiCl3] and [(bpy)2BiX3] (X = Br, I) are assigned and discussed in relation to the structures of the complexes.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LXXI Synthesis, Spectroscopy and Structural Systematics of Some 1 : 2 Binuclear Adducts of Silver(I) Compounds with Triphenylarsine, [(Ph3As)2Ag(µ-X)2Ag(AsPh3)2], X = Cl, Br, I, SCN

1997 ◽  
Vol 50 (6) ◽  
pp. 627 ◽  
Author(s):  
Graham A. Bowmaker ◽  
Effendy ◽  
John D. Kildea ◽  
Eban N. de Silva ◽  
Allan H. White
Keyword(s):  
Infrared Spectra ◽  
Structural Characterization ◽  
Room Temperature ◽  
Far Infrared ◽  
Lewis Base ◽  
X Ray ◽  
C 23 ◽  
Pseudo Halides ◽  
Far Infrared Spectra

The syntheses and room-temperature single-crystal X-ray structural characterization of binuclear 1 : 2 adducts formed between silver(I) (pseudo-)halides, AgX, and triphenylarsine, AsPh3, for X = Cl, Br, I, SCN (1)–(4), are described. The chloride (1), obtained from 2-methylpyridine, is triclinic, P-1, a 10·410(2), b 12·716(2), c 14·196(6) Å, α 113·38(2), β 109·41(2), γ 75·08(1)°, Z = 1 (dimer); conventional R on F was 0·037 for No 3979 independent ‘observed’ (I > 3σ(I)) reflections. The bromide (2a), obtained from 2,6-dimethylpyridine, and iodide (3), obtained from a mixture of AgI/saturated KI in MeOH solutions, are isomorphous, monoclinic, P 21/c a≈ 24·2, b ≈ 13·9, c ≈ 20·2 Å, β ≈ 109·5°, Z = 4 dimers; R was 0·046 and 0·044 for No 5670 and 6039 respectively. The thiocyanate (4) has a similar cell, a 24·12(1), b 12·558(8), c 23·244(4) Å, β 110·11(3)°, Z = 4 dimers, R being 0·044 for No 7956; one of the thiocyanate ligands (which bridge in Ag-SCN-Ag mode) is disordered. A second polymorph of the bromide (2b) (from a mixture of AgBr/saturated KBr in H2O) is also monoclinic, P 21/c, a 14·121(8), b 25·577(3), c 21·968(2) Å, β 125·54(3)°, Z = 4 dimers (R was 0·047 for No 5715). Ag–As range between 2·568(1) and 2·633(1) Å throughout the series; in the isomorphous bromide and iodide, values increase slightly: 2·578(1)–2·611(1), cf. 2·601(2)-2·633(1) Å respectively. Ag–X are 2·568(2)-2·670(2) (Cl); 2·688(2)–2·715(2) (Br); 2·828(2)–2·856(1) Å (I); Ag-S, N for the ordered SCN group are 2·646(3), 2·255(6) Å. A redetermination of improved precision (R 0·035, No 6030) is reported for the triphenylphosphine/thiocyanate analogue. The far-infrared spectra of [(Ph3As)2Ag(µ-X)2Ag (AsPh3)2] show v(AgX) bands at 185, 145 (X = Cl), 145, 130, 106 (X = Br) and 121 cm-1 (X = I). The splittings and band widths reflect a decrease in the degree of distortion of the Ag(µ-X)2Ag units from a symmetrically bridged structure from X = Cl to I.

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