Lithium monoxide anion: A ground-state triplet with the strongest base to date

doi:10.1073/pnas.0801393105

Lithium monoxide anion: A ground-state triplet with the strongest base to date

*Department of Chemistry, University of Minnesota, Minneapolis, MN 55455; and
^†School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney NSW 2006, Australia

Edited by W. Carl Lineberger, University of Colorado, Boulder, CO, and approved March 13, 2008 (received for review February 12, 2008)

Abstract

Lithium monoxide anion (LiO⁻) has been generated in the gas phase and is found to be a stronger base than methyl anion (CH₃ ⁻). This makes LiO⁻ the strongest base currently known, and it will be a challenge to produce a singly charged or multiply charged anion that is more basic. The experimental acidity of lithium hydroxide is ΔH°_acid = 425.7 ± 6.1 kcal·mol⁻¹ (1 kcal = 4.184 kJ) and, when combined with results of high-level computations, leads to our best estimate for the acidity of 426 ± 2 kcal·mol⁻¹.

Footnotes

^§To whom correspondence may be addressed. E-mail: radom{at}chem.usyd.edu.au or kass{at}umn.edu
Author contributions: Z.T., B.C., M.B.S., L.R., and S.R.K. performed research; Z.T., B.C., M.B.S., L.R., and S.R.K. analyzed data; L.R. and S.R.K. designed research; and L.R. and S.R.K. wrote the paper.
↵ ^‡Present address: Institute of High Performance Computing, Singapore 117528.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0801393105/DCSupplemental.