Accumulated proton-donating ability of solvent molecules in proton transfer

J Am Chem Soc. 2010 Jan 13;132(1):297-302. doi: 10.1021/ja907491u.

Abstract

Solvent-inventory experiments on the excited-state proton transfer of a 7-hydroxyquinoline molecule complexed cyclically with two alcohol molecules in the host medium of n-alkane have been carried out with various combinations of alcohols having different proton-donating abilities. Alcohol molecules participating in the hydrogen-bonded chain of the cyclic complex accelerate proton transfer in a concerted fashion by accumulating their proton-donating abilities. The rate-determining deprotonation of the alcohol molecule hydrogen-bonded directly to the imino group of 7-hydroxyquinoline is stimulated by the push-ahead effect of the next alcohol molecule in the hydrogen-bonded chain. Our results provide a clue at the level of molecules on the fundamental mechanistic elucidation of proton transport occurring through a proton wire consisting of diverse amino acids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols / chemistry
  • Hydrogen Bonding
  • Kinetics
  • Protons*
  • Quinolines / chemistry
  • Solvents / chemistry*

Substances

  • Alcohols
  • Protons
  • Quinolines
  • Solvents
  • quinoline