Solvent effects in the 2JHH, 3JHH, 1JNC and 2JNC coupling constants in the NMR spectrum of acetylcholine chloride
Abstract
Coupling constant values ( JNH and JNC) obtained from 1H and 13C NMR spectra of acetylcholine chloride (ACh) in several solvents with a wide range of permittivity constants ( ɛ) are remarkably invariant, indicating the absence of solvent effects in the conformational equilibrium of this compound. The values show that the OCH 2CH 2N + system occurs in a gauche arrangement. JNH and JNC are observable in most solvents, but not in chlorine-containing solvents, and are not dependent on solvent viscosity. This behavior was explained using data from T1 measurements. The measurement of NMR diffusion coefficients shows that ACh has a greater tendency to aggregate when dissolved in chlorinated solvents, a fact that could explain the observed differences in 14N T1.
- Publication:
-
Journal of Molecular Structure
- Pub Date:
- September 2006
- DOI:
- 10.1016/j.molstruc.2006.03.012
- Bibcode:
- 2006JMoSt.797...44S