4C6 - Concentration and temperature dependences of spin-lattice relaxation times in ruby at helium temperatures: Relaxation in a zero magnetic field

1966 ◽  
Vol 2 (9) ◽  
pp. 409-412 ◽  
Author(s):  
A. Manenkov ◽  
Yu. Danileiko
Keyword(s):  
Magnetic Field ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Zero Magnetic Field ◽  
Spin Lattice ◽  
Temperature Dependences

scholarly journals Effect of magnetic field strength on the linewidth and spin-lattice relaxation time of the thiocyanate carbon of cyanylated β-lactoglobulin B: optimization of the experimental parameters for observing thiocyanate carbons in proteins

1995 ◽  
Vol 306 (2) ◽  
pp. 531-535
Author(s):  
J P G Malthouse ◽  
P Phelan
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Chemical Shift Anisotropy ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Field Strengths

The linewidths and spin-lattice relaxation times of the 13C-n.m.r. signal at 109.7 p.p.m. due to the thiocyanate carbon of intact [cyanato-13C]cyanylated-beta-lactoglobulin-B have been determined at magnetic field strengths of 1.88, 6.34 and 11.74 T as well as the spin-lattice relaxation times of its backbone alpha-carbon atoms. The linewidths were directly proportional to the square of the magnetic field strength and we conclude that, at magnetic field strengths of 6.34 T or above, more than 70% of the linewidth will be determined by chemical-shift anisotropy. We estimate that the spin-lattice relaxation time resulting from the chemical-shift anisotropy of the thiocyanate carbon is 1.52 +/- 0.1 s and we conclude that for magnetic field strengths of 6.34 T and above the observed spin-lattice relaxation time of the thiocyanate carbon will be essentially independent of magnetic field strength. Using the rigid-rotor model we obtain estimates of the rotational correlation time of [cyanato-13C]cyanylated-beta-lactoglobulin-B and of the chemical-shift anisotropy shielding tensor of its thiocyanate carbon. We have calculated the linewidths and spin-lattice relaxation times of thiocyanate carbons at magnetic field strengths of 1.88-14.1 T in proteins with M(r) values in the range 10,000-400,000. The effects of magnetic field strength on the resolution and signal-to-noise ratios of the signals due to thiocyanate carbons attached to proteins of M(r) greater than 10,000 are discussed.

Interrelation Between Molecular Motions and Structure in Solid Trimethylamine-boron-trichloride as Studied by NMR

1992 ◽  
Vol 47 (11) ◽  
pp. 1157-1160
Author(s):  
S. Głowinkowski ◽  
, S. Jurga ◽  
E. Szcześniak
Keyword(s):  
Molecular Structure ◽  
Relaxation Times ◽  
Activation Parameters ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Molecular Motions ◽  
Boron Trichloride ◽  
Second Moment ◽  
Spin Lattice ◽  
Temperature Dependences

AbstractThe temperature dependences of proton second-moment and spin-lattice relaxation times (T1 and T1ρ) have been measured in solid (CH3)3NBCl3. The nature of reorientation processes occurring in the complex has been established and the activation parameters determined. The motions are discussed in relation to the molecular structure of the complex

Ionic Dynamics in LiNO2 Studied by 7Li and 15N Solid NMR

1999 ◽  
Vol 54 (8-9) ◽  
pp. 519-523 ◽  
Author(s):  
Hisashi Honda ◽  
Shin'ich Ishimaru ◽  
Ryuichi Ikeda
Keyword(s):  
Relaxation Times ◽  
Activation Parameters ◽  
Lattice Relaxation ◽  
The Self ◽  
Spin Lattice Relaxation ◽  
Plastic Crystal ◽  
Self Diffusion ◽  
Spin Lattice ◽  
Solid Nmr ◽  
Temperature Dependences

The temperature dependences of 7Li and 15N NMR spin-lattice relaxation times and spectra in LiNO2 were measured in the range 120 K -473 K (m.p.). The 180°-flip motion of NO2-- ions along or perpendicular to the molecular C2 -axis and the self-diffusion of Li+ ions (activation energies of 42 -44 and 100 kJ mol-1 , respectively) were observed in this range. From the comparison of the observed activation parameters with those reported for plastic phases of alkali metal nitrites, a new characteristic of the plastic crystal was obtained.

Temperature Dependences of NQR Frequencies and Nuclear Quadrupole Relaxation Times of Chlorine in 2,6-Lutidinium Hexachlorotellurate (IV) as Studied by Pulsed NQR Techniques

1990 ◽  
Vol 45 (3-4) ◽  
pp. 485-489
Author(s):  
Keizo Horiuchi ◽  
Takashige Shimizu ◽  
Hitomi Iwafune ◽  
Tetsuo Asaji ◽  
Daiyu Nakamura
Keyword(s):  
Phase Transition ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
Quadrupole Relaxation ◽  
Spin Lattice ◽  
Resonance Frequencies ◽  
Temperature Dependences ◽  
Nuclear Quadrupole

Abstract The temperature dependences of the 35Cl NQR frequencies vQ and the nuclear quadrupole spin-lattice relaxation times T1Q in 2,6-lutidinium hexachlorotellurate (IV) was observed at various temperatures between 80 and 343 K. This crystal undergoes a phase transition at Tc = 229 K. A single and three pairs of 35Cl NQR frequencies were observed above and below Tc , respectively. The hysteresis of the phase transition and a discontinuity in the temperature dependence of the resonance frequencies at Tc indicate that this phase transition is of first order. Although the resonance frequencies of the pairs in the low temperature phase are very close to one another, T1Q and below Tc could be accurately determined by measuring the Fourier transform spectra of each line. Above ca. 250 K, T1Q showed an exponential decrease which is attributable to the overall reorientational motion of [TeCl6]2- with an activation energy of 82 kJ mol-1

Chlorine-35 NQR Study of a Structural Phase Transition in (ND4)2PdCl6

1998 ◽  
Vol 53 (6-7) ◽  
pp. 514-517 ◽  
Author(s):  
Yoshio Kume ◽  
Tetsuo Asaji
Keyword(s):  
Phase Transition ◽  
Structural Phase ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
Spin Lattice ◽  
First Order Phase Transition ◽  
Temperature Dependences ◽  
First Order Phase

Abstract Temperature dependences of 35Cl NQR frequencies and spin-lattice relaxation times were measured at 4.2 to 400 K for natural and deuterated ammonium hexachloropalladate. It was confirmed that only the deuterated salt undergoes a first order phase transition at 30 K. The crystal structure of the low-temperature phase is predicted to be the same as that of the deuterated ammonium hexachloroplatinate and hexachloroplumbate. The mechanism of the deuteration-induced phase transition is discussed.

A 35Cl NQR Study on Exchange Interactions between Paramagnetic [IrCl6]2– Ions

2002 ◽  
Vol 57 (6-7) ◽  
pp. 431-434 ◽  
Author(s):  
Hiroshi Miyoshi ◽  
Keizo Horiuchi ◽  
Ryuichi Ikeda
Keyword(s):  
Relaxation Times ◽  
Exchange Interactions ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
35Cl Nqr ◽  
Temperature Dependences ◽  
Field Fluctuations ◽  
Paramagnetic Ions ◽  
Exchange Parameters

The 35Cl and 37Cl NQR frequencies and spin-lattice relaxation times T1Q in paramagnetic M2IrCl6 (M = NH4, Cs) were measured at 4 - 350 K. The observed temperature dependences were attributed to EFG fluctuations caused by lattice vibrations and magnetic field fluctuations caused by paramagnetic ions. The exchange parameters in the NH4 and Cs salts were calculated from 35Cl NQR T1Q to be 8.6 K and 1.8 K respectively. 37Cl data yielded 9.1 K and 2.1 K respectively. The obtained lattice constant dependence of J values was explained by considering Ir-Cl Cl-Ir superexchange interaction

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