Premium
Ion pairing and the rotational mobility of organic ions in solution
Author(s) -
Levy George C.,
TerryBailey J.
Publication year - 1980
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270130604
Subject(s) - ion , solvation , chemistry , formate , chemical physics , dipole , ionic bonding , solvent , ionic radius , computational chemistry , organic chemistry , catalysis
Carbon‐13 dipolar spin‐lattice relaxation times can be used to study microscopic ion mobility in solvent‐separated and contact ion‐pair systems. Two chemically stable ion pairs were studied. Cyclohexylammonium formate observed in a number of solvents allows correlation of relaxation times—and therefore ion rotational mobility—with empirical solvent polarity indices. Estimation of the effective anion radius shows a change of a factor of three in size arising from solvation/ion‐pairing effects. Trimesate trianion (1,3,5‐tricarboxybenzene) with differing cations present in solution is a good probe of changes in the solvation sphere and degree of ion aggregation. Variable temperature studies give an activation energy for overall ionic reorientation of c. 5 kcal/mol.