Molecular Motion in Azulene and the Azulenes–(s)-Trinitrobenzene Molecular Complex in the Solid State

1973 ◽  
Vol 51 (22) ◽  
pp. 3774-3780 ◽  
Author(s):  
C. A. Fyfe ◽  
G. J. Kupferschmidt
Keyword(s):  
Solid State ◽  
Molecular Motion ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spectral Parameters ◽  
X Ray ◽  
Spin Lattice ◽  
Wide Line ◽  
Experimental Values

Molecular motion of azulene in its own molecular crystal and in its complex with trinitrobenzene has been shown from wide-line n.m.r. and spin–lattice relaxation time measurements to occur in the solid state. Calculations of the n.m.r. spectral parameters based on a model where the azulene molecules are reorienting in their molecular planes by 180° jumps give satisfactory agreement with experimental values. The results are discussed with respect to the available X-ray data.

Characterization of Molecular Motion in the Solid State by Carbon-13 Spin–Lattice Relaxation Times

2000 ◽  
Vol 142 (2) ◽  
pp. 229-240 ◽  
Author(s):  
Samuel J Varner ◽  
Robert L Vold ◽  
Gina L Hoatson
Keyword(s):  
Solid State ◽  
Molecular Motion ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

Film Characterization of Ultra Low-k Dielectrics Modified by UV Curing with Different Wavelength Bands

2006 ◽  
Vol 914 ◽  
Author(s):  
Masazumi Matsuura ◽  
Kinya Goto ◽  
Noriko Miura ◽  
Shinobu Hashii ◽  
Koyu Asai
Keyword(s):  
Molecular Motion ◽  
Uv Curing ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Raman Analysis ◽  
Spin Lattice ◽  
Ft Ir ◽  
Low K

AbstractThis paper describes film characterization of Ultra Low-k (ULK) dielectrics modified by UV curing with different wavelength bands. We have demonstrated UV hardening of ULK-SiOC (k=2.65) with two types of UV bulbs (UV-X and UV-Y) and the UV modifications of ULK-SiOC film properties are characterized by using FT-IR spectroscopy, 29Si Solid-state NMR spectroscopy and Raman spectroscopy. FT-IR and NMR analyses reveal that UV-Y curing is preferable for UV curing modification of ULK-SiOC. UV-Y curing increases Q mode peak in NMR, resulting in the enhanced Si-O crosslinking, while UV-X curing increases TH mode and TOR mode peaks. Spin lattice relaxation time T1 for 29Si is decreased with UV curing. This result indicates that UV curing enhances molecular motion in Si-O network. Raman analysis shows that UV curing increases amorphous carbon groups, which corresponds to the enhanced molecular motion in Si-O network.

Molecular Motion in Solid Tetrapropylammonium Bromide and Iodide

1992 ◽  
Vol 47 (11) ◽  
pp. 1115-1118 ◽  
Author(s):  
S. Lewicki ◽  
B. Szafranska ◽  
Z. Pajak
Keyword(s):  
Molecular Motion ◽  
Solid Phase ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Methyl Groups ◽  
Methyl Group ◽  
Spin Lattice ◽  
Tetrapropylammonium Bromide ◽  
Solid Phase Transition

Abstract The proton NMR second moment and spin-lattice relaxation time for tetrapropylammonium bromide and iodide have been measured over a wide temperature range. A solid-solid phase transition related to the onset of cation tumbling was found for both salts and confirmed by DTA. In the low temperature phases methyl group reorientation was evidenced. For iodide a dynamic nonequivalence of the methyl groups and the onset of ethyl groups motion was also discovered

Proton Magnetic Resonance and Molecular Motion in Solid Methyl-Piperidines and Piperazines

1977 ◽  
Vol 32 (8) ◽  
pp. 882-885 ◽  
Author(s):  
R. Schüler ◽  
L. Brücher ◽  
W. Müller-Warmuth
Keyword(s):  
Proton Magnetic Resonance ◽  
Molecular Motion ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Methyl Group ◽  
Spin Lattice ◽  
H Nmr ◽  
Second Moments ◽  
Line Narrowing

Abstract The 1H-NMR spin-lattice relaxation time and lineshape in solid 2-, 3-, and 4-methyl-piperidine, in 2-and N-methyl-piperazine, and in NN′-diinethyl-piperazine has been measured from low temperatures to the melting point. For all cases, the experimental data can be described by classical rotation of the methyl group. Activation energies governing this motion are between 9 and 14 kJ/mole. Second moments are reduced from about 25 G2 to 17 G2. No further line-narrowing was observed.

35Cl NQR and Molecular Motion in Solid C6X5Cl (X = H, F)

1992 ◽  
Vol 47 (1-2) ◽  
pp. 330-332 ◽  
Author(s):  
A. D. Gordeev ◽  
G. B. Soifer ◽  
A. P. Zhukov
Keyword(s):  
Relaxation Time ◽  
Molecular Motion ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Activation Energies ◽  
Spin Lattice Relaxation ◽  
Melting Points ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
35Cl Nqr

AbstractThe 35Cl NQR frequency and spin-lattice relaxation time of solid chlorobenzene and chloropentafluorobenzene at temperatures from 77 K to the melting points have been measured and explained by thermoactivated librations and reorientations of the molecules around the normal to their plane. The activation energies of these motions have been estimated

Protonenresonanzuntersuchungen über innermolekulare Bewegungen, Phasenumwandlungen und Entglasungsvorgänge in festen Äthern

1966 ◽  
Vol 21 (8) ◽  
pp. 1231-1240 ◽  
Author(s):  
K. Grude ◽  
J. Haupt ◽  
W. Müller-Warmuth
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Lattice Relaxation ◽  
Relaxation Mechanism ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Small Range ◽  
Second Moment ◽  
Spin Lattice ◽  
Line Shapes

Proton magnetic resonance investigations on solid dimethylether (DM) , diethylether (DE) , dipropylether (DP), diisopropylether (DIP), dibutylether (DB), dimethoxymethane (DMM), diethoxymethane (DEM), dimethoxyethane (DME), diethoxyethane (DEE), acetaldehyde (ACA) and diethylketone (DEK) yielded information on molecular motion, solid state phase transitions and deglassing processes. The temperature-dependence of the spin-lattice relaxation time and the second moment was studied between the melting point and 77 °K using radiofrequency pulse techniques. Both spin-lattice relaxation and line shapes are governed by dipolar interactions which are modulated in time by hindered rotations of CH3-groups. The parameters for this relaxation mechanism are given in detail. Concerning the general results it was possible to distinguish between three cases : a) substances that form only one crystalline phase in the solid state (DM, DIP, DEM, DME, ACA, and DEK); b) ethers that form only a vitreous state (DP and DEE) and c) ethers that form both crystalline and vitreous states depending on the way in which the liquid was cooled. In the last case a pronounced decrease of the second moment of the absorption line was observed near the phase transition from the vitreous to the polycrystalline state. This means that within a small range of temperatures far below the melting point some kind of melting of the glass occurs before the crystal is formed.

A study of molecular motion in tetramethylphosphonium halides by proton magnetic resonance

1976 ◽  
Vol 54 (12) ◽  
pp. 1985-1990 ◽  
Author(s):  
T. T. Ang ◽  
B. A. Dunell
Keyword(s):  
Molecular Motion ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Methyl Group ◽  
X Ray ◽  
Spin Lattice ◽  
Second Moments

Spin–lattice relaxation times of tetramethylphosphonium chloride, bromide, and iodide were measured between 100 and 500 K and the two minima in T1 found for each compound have been assigned to methyl group reorientation and whole cation tumbling. The second moments also indicate that the cations are tumbling isotropically at nmr frequencies in the upper half of this temperature range, and suggest that librational oscillation of the whole cation occurs at frequencies at least of the order of 105 s−1 near 150 K. The energy barriers for both methyl group reorientation and isotropic tumbling decrease from chloride to bromide but increase when one goes from bromide to iodide. Powder photograph X-ray diffraction analysis indicates that the chloride and bromide have hexagonal crystal structures (a and c measured), but that the iodide has lower, undetermined symmetry.

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