• Home
  • Search Results
  • Symmetry of N-H-N hydrogen bonds in 1,8-bis(dimethylamino)naphthalene.H+ and 2,7-dimethoxy-1,8-bis(dimethylamino)naphthalene.H+.

Symmetry of N-H-N hydrogen bonds in 1,8-bis(dimethylamino)naphthalene.H+ and 2,7-dimethoxy-1,8-bis(dimethylamino)naphthalene.H+.

Journal of the American Chemical Society (2001-07-06)
C L Perrin, B K Ohta
ABSTRACT

In solution, are the hydrogen bonds in monoprotonated N,N,N',N'-tetramethyl-1,8-naphthalenediamines single- or double-well? To answer this question, isotopic perturbation of equilibrium is applied to a mixture of -d(0), -d(3), -d(6), -d(9), and -d(12) isotopologs. The N-methyls of the 2,7-dimethoxy analogue show intrinsic isotope shifts from the geminal CD(3) and from only one distant CD(3), an unusual stereochemical effect transmitted across the hydrogen bond. The (13)C NMR splittings and intensities at the various ring carbons of both ions are consistent with perturbation isotope shifts, intrinsic shifts, or a combination of both. The perturbation shifts mean that the protons reside in a double-minimum potential and that each ion is a pair of rapidly interconverting tautomers. The significance of this result for the role of low-barrier hydrogen bonds in enzyme-catalyzed reactions is discussed.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
2,7-Dimethoxynaphthalene, 98%

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

MilliporeSigma

Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.