Kinetic and equilibrium lithium acidities of arenes: theory and experiment

J Phys Chem A. 2010 Aug 26;114(33):8793-7. doi: 10.1021/jp101791e.

Abstract

Kinetic acidities of arenes, ArH, measured some time ago by hydrogen isotope exchange kinetics with lithium cyclohexylamide (LiCHA) in cyclohexylamine (CHA) show a wide range of reactivities that involve several electronic mechanisms. These experimental reactivities give an excellent Brønsted correlation with equilibrium lithium ion pair acidities (pK(Li)) derived as shown recently from computations of ArLi.2E (E = dimethyl ether). The various electronic mechanisms are well modeled by ab initio HF calculations with modest basis sets. Additional calculations using NH(3) as a model for CHA further characterize the TS of the exchange reactions. The slopes of Brønsted correlations of ion pair systems can vary depending on the nature of the ion pairs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acids / chemistry*
  • Ammonia / chemistry
  • Cyclohexylamines / chemistry*
  • Kinetics
  • Lithium / chemistry*
  • Molecular Dynamics Simulation
  • Molecular Structure
  • Quantum Theory

Substances

  • Acids
  • Cyclohexylamines
  • Ammonia
  • Lithium