Electric reaction field of a molecular quadrupole and solvent chemical shift
Abstract
1 H nuclear magnetic resonance chemical-shift measurements on benzene and acetylene in a series of solvents are presented. We have tried to separate the electric-field contribution, σE, from the total solvent chemical shift of these solutes possessing a molecular quadrupole.
Twenty years ago Buckingham proposed a theoretical relation between the electric reaction field of a molecular quadrupole and the chemical shift of a proton in that molecule, but his relation has not been tested experimentally. The isolated electric-field solvent shifts from the quadrupoles benzene and acetylene appear to be in reasonable agreement with the slightly extended theory. A discussion of the difference is given.