Crystal Structure and Nuclear Quadrupole Resonance. The Bond Length C - Cl and 35Cl NQR

1990 ◽  
Vol 94 (4) ◽  
pp. 497-513 ◽  
Author(s):  
Stefanie Brummer ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Nuclear Quadrupole Resonance ◽  
Quadrupole Resonance ◽  
35Cl Nqr ◽  
Nuclear Quadrupole

35Cl and 37Cl Pure Quadrupole Resonance in α-CH2ClCOOH: Hydrogen Bonding and Chlorine Isotope Effect

1978 ◽  
Vol 33 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Helmut Rager
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Temperature Dependence ◽  
Bond Length ◽  
Nuclear Quadrupole Resonance ◽  
Isotope Effect ◽  
Unit Cell ◽  
Chlorine Atoms ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

The temperature dependence of the pure nuclear quadrupole resonance of 35Cl and 37Cl in solid α-CH2ClCOOH has been measured from 77 K to 298 K. The NQR spectrum consists of a doublet arising from the two nonequivalent chlorine atoms in the unit cell. The temperature dependence was calculated using the Bayer-Kushida theory which gives a satisfactory fit to the NQR spectra in the temperature range investigated. From the NQR data evidence of an isotope effect was found for both nonequivalent chlorine atoms. The isotope effect depends on the C-Cl bond length and its direction probably on the state of binding of the chlorine atoms. The NQR results and their interpretation are consistent with the crystal structure of α- CH2ClCOOH.

35Cl NQR Study of Guest Dynamics in Thiourea-CCl4 Inclusion Complex

1990 ◽  
Vol 45 (3-4) ◽  
pp. 519-522 ◽  
Author(s):  
Takasuke Matsuo ◽  
Masako Sekii ◽  
Hiroshi Suga ◽  
Nobuo Nakamura ◽  
Hideaki Chihara
Keyword(s):  
Activation Energy ◽  
Inclusion Complex ◽  
Nuclear Quadrupole Resonance ◽  
Intensity Ratio ◽  
Resonance Frequencies ◽  
Quadrupole Resonance ◽  
35Cl Nqr ◽  
Nuclear Quadrupole

Abstract35Cl nuclear quadrupole resonance measurements on thiourea-CCl4 inclusion complex yielded two resonance lines with intensity ratio 1:3. This indicates that the guest CCl4 molecule occupies the three-fold symmetry site in the channel formed by the thiourea framework. The resonance frequencies closely follow Bayer's equation between 4.2 K and 27 K. At higher temperatures the resonance lines faded out. This is attributed to the onset of reorientation of the CCl4 molecule. The activation energy for this motion was estimated to be 6 kJ mol-1 .

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