Nonbenzenoid aromatic systems. VII. Reactions of azulenes with ethylene oxide or trimethylene oxide and Lewis acids

1972 ◽  
Vol 37 (19) ◽  
pp. 2957-2959 ◽  
Author(s):  
Richard N. McDonald ◽  
Herbert E. Petty
Keyword(s):  
Ethylene Oxide ◽  
Lewis Acids ◽  
Trimethylene Oxide ◽  
Aromatic Systems

Coordination of silicon tetrafluoride with alicyclic ethers and dimethyl ether

1968 ◽  
Vol 46 (6) ◽  
pp. 987-993 ◽  
Author(s):  
J. P. Guertin ◽  
M. Onyszchuk
Keyword(s):  
Ethylene Oxide ◽  
Dimethyl Ether ◽  
Condensed Phase ◽  
Silicon Tetrafluoride ◽  
Relative Order ◽  
Trimethylene Oxide

Tensimetric titrations at −78° of silicon tetrafluoride with ethylene oxide, trimethylene oxide, tetrahydrofuran, tetrahydropyran, and dimethyl ether prove the formation of only 1:2 complexes, SiF4•2-(ether). All are unstable at 25° and either dissociate completely, as do SiF4•2(CH2)4O, SiF4•2(CH2)5O, and SiF4•2(CH3)2O, or decompose into SiF4 and a polymethylene oxide polymer, as do SiF4•2(CH2)2O and SiF4•2(CH2)3O. Silicon tetrafluoride does not coordinate with 1,4-dioxane in the range −94 to 25° and less than 1 atm pressure. Condensed phase heats of dissociation of SiF4•2(ether) complexes follow the order (CH2)3O > (CH2)4O > (CH2)5O ≥ (CH2)2O > (CH3)2O, which suggests that this is the relative order of basicities towards SiF4.

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.

Far infrared absorption and rotational vibrations of the guest molecules in structure I clathrate hydrates between 4.3 and 100 K

1977 ◽  
Vol 55 (10) ◽  
pp. 1777-1785 ◽  
Author(s):  
John E. Bertie ◽  
Stephen M. Jacobs
Keyword(s):  
Ethylene Oxide ◽  
Guest Molecule ◽  
Signal To Noise Ratio ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Force Constants ◽  
Clathrate Hydrates ◽  
High Signal ◽  
Guest Molecules ◽  
Trimethylene Oxide

The infrared spectra between 330 and 15 cm−1 of the structure I clathrate hydrates of ethylene oxide, cyclopropane, and trimethylene oxide, at 4.3 K are presented. The spectra have an unusually high signal-to-noise ratio made possible by a Michelson interferometer and a silicon bolometer detector which operates at 1.2 K. Rotational vibrations of the guest molecules were observed at 65.0 and 35.6 cm−1 for ethylene oxide and at 69 and 50 cm−1 for trimethylene oxide. Inter-guest coupling of rotational vibrations is small and the two frequencies are assigned to vibrations about different inertial axes. The resulting force constants are 487 and 264 ferg rad−2 for ethylene oxide and 1190 and 1130 ferg rad−2 for trimethylene oxide and are discussed in relation to the barriers to reorientation of the guest molecule. The bands due to these vibrations are fairly sharp at 4.3 K, but are broad and poorly defined at 100 K. The guest and water vibrations interact predominantly through their transition dipoles, although the main contribution to the force constants of the rotational vibrations is from steric forces. The absorption by the water vibrations above 100 cm−1 is very similar for ethylene oxide and cyclopropane hydrates but significantly different for trimethylene oxide hydrate. Strong objections exist to the obvious interpretations of this difference which remains unexplained.

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

Abstract Detailed 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, v OD (HDO), and of the fully deuterated forms, v OD(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 v OH(H2O)v OD(D2O), and v R(D2O) bands are essentially the same for structures I and II, while the v OD(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 v OD(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.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

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