Intermolecular and intramolecular motions in the solvation spheres of some ions in methyl and ethyl alcohol

Abstract

Proton relaxation rates in solutions MnCl2-CD3OH and MnCl2-C2D5OH are reported and from these data rotational correlation times for the solvation complexes are determined. Proton and deuteron relaxation rates for the hydroxyl, methylene, and methyl group in solutions of Mg(C104)2, CaCl2, NaC104, Nal, and KI in methyl alcohol and ethyl alcohol are reported, and correlation times for the various groups are determined. The various correlation times are compared with one another and, in those cases where they differ for a given solvation complex, intermolecular or intramolecular motions are postulated. The results are also compared with predictions derived from pertinent theories currently available. It is found that the description of the internal motions by the theory is not satisfactory in all cases.

Internal Motion in Liquid Ethanol and some Other Alcohols, Separation of Contributions by Added Glycerol

“…The temperature gradient over the sample volume was ± 1 K at maximum and the total uncertainty was estimated to be ± 1.5 K. The resulting total uncertainty in 7j is estimated to be 5 -10%. 3. Results…”

“…This is in a certain contrast to our previous paper [4] where in Eqs. (5) and (6) the coefficients of the exponentials were called a} and a] and where these coefficients were understood as being functions of the angles derived from molecular geometry. Thus the use of the wj implies the statement: It may be that no geometric assignments can be given to them, yet the geometric interpretability will be examined.…”

“…Furthermore, for the CH2 and CH3 groups under varying conditions certain relations between the various as required by the theory could not be verified [3,7], and finally there do already exist experimental investigations which did not reveal the multi-term structure of Eq. (1) [4,[16][17][18], Now the fundamental problem with which we are confronted is to get information about a kind of molecular motion the time constants of which are two to three orders of magnitude shorter than the observation time inherent in the method used, which is the reciprocal nuclear magnetic resonance frequency, co~l.…”

Effect of different sodium halides on the self-association of tertiary butanol in water

“…To use this as a quantification of molecular self-association, we follow the approach of Hertz and co-workers. [25][26][27][28] Assuming that the only protons in the system are those in the TBA molecules, we may describe the molecular distribution by the protonproton pair correlation function g HH ͑r͒. We then consider the weighted integral…”

Adding salt to an aqueous solution of t-butanol: Is hydrophobic association enhanced or reduced?

“…Moreover, it is obvious that it also depends strongly on the average distance between the spins and is hence sensitive to changing inter-and intramolecular pair distribution functions. 40,41 In addition, the r −6 weighting introduces a particular sensitivity to changes occurring at short distances. For convenience, one may divide the spins j into different classes according to whether they belong to the same molecule as spin i, or not, thus arriving at an inter-and intramolecular contribution to the relaxation rate…”