Proton Affinities of Anionic Bases: Trends Across the Periodic Table, Structural Effects, and DFT Validation

Marcel Swart; F Matthias Bickelhaupt

doi:10.1021/ct0502460

Proton Affinities of Anionic Bases: Trends Across the Periodic Table, Structural Effects, and DFT Validation

J Chem Theory Comput. 2006 Mar;2(2):281-7. doi: 10.1021/ct0502460.

Authors

Marcel Swart¹, F Matthias Bickelhaupt¹

Affiliation

¹ Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands.

PMID: 26626515
DOI: 10.1021/ct0502460

Abstract

We have carried out an extensive exploration of the gas-phase basicity of archetypal anionic bases across the periodic system using the generalized gradient approximation of density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton affinities and related thermochemical quantities: BP86/QZ4P//BP86/TZ2P is shown to yield a mean absolute deviation of 1.6 kcal/mol for the proton affinity at 0 K with respect to high-level ab initio benchmark data. The main purpose of this work is to provide the proton affinities (and corresponding entropies) at 298 K of the anionic conjugate bases of all main-group-element hydrides of groups 14-17 and periods 2-6. We have also studied the effect of stepwise methylation of the protophilic center of the second- and third-period bases.