Showing 1 - 10 of 12
A stochastic differential equation study of nuclear magnetic relaxation by spin-rotational interactions was successfully completed for spherical, symmetric rotator and linear molecules. This theory has now been extended to asymmetric rotator molecules by first establishing the conditions under...
Persistent link: https://www.econbiz.de/10010873183
A way is proposed to describe all the unsual features of IR and FIR spectra and to relate them to free path inertial effects and those attributable to the finite times of molecular collisions. In the case of rotational diffusion these finite times may be deduced from the measured values of...
Persistent link: https://www.econbiz.de/10010873190
The theory, elaborated in previous works is applid to the calculation of liquid water wideband (0 ν/cm−1 1000) dielectric spectra. These comprise the Debye relaxation region at the centimeter/millimeter wavelengths and the two-humped absorption coefficient frequency dependence in the far...
Persistent link: https://www.econbiz.de/10011057300
It is shown that the problem of calculating times related to nuclear magnetic spin-rotational interactions may be solved for the symmetric rotator model of a molecule by employing the method already proposed in a general manner for asymmetric molecules that undergo rotational thermal motion....
Persistent link: https://www.econbiz.de/10010584712
A theoretical study is made of nuclear magnetic relaxation by dipole-dipole interactions, when the molecules containing the dipoles are subject to random thermal motion. Relaxation rates are expressed in terms of spectral densities for both intermolecular and intramolecular interactions....
Persistent link: https://www.econbiz.de/10010584844
The mathematical methods based on stochastic differential equations and the rotation operator, which were developed for the study of rotational Brownian motion and its implications for dielectric dispersion and absorption, are extended so as to yield ensemble averages of certain products of...
Persistent link: https://www.econbiz.de/10010585186
It is shown that to a high degree of accuracy the complex relativity permittivity for a gas dielectric or for a liquid dielectric in very dilute solution in a nonpolarsolvent is given theoretically for symmetric polar molecules by the modification of a relation, which essentially goes back to...
Persistent link: https://www.econbiz.de/10010585295
A procedure is proposed for calculating in Debye approximation physical quantities related to steady state random thermal motion. The results are expressed in terms of the stochastic rotation operator. Explicit expressions are derived for this operator and its ensemble average in the case of a...
Persistent link: https://www.econbiz.de/10010585338
A theory of nuclear magnetic relaxation by anisotropic chemical shift is based on an inertial theory of rotational Brownian motion of a molecule of arbitrary shape immersed in a liquid. Explicit expressions are derived for spherical, linear and symmetric rotator molecular models. These provide a...
Persistent link: https://www.econbiz.de/10010585441
Spectral densities of spherical harmonics arising from the rotational Brownian motion of molecules are calculated. The molecules are supposed to be spherical or linear, and account is taken of the influence of their inertia. When the results for a spherical molecule are applied to nuclear...
Persistent link: https://www.econbiz.de/10010585555