title: Steric effects on alkyl cation affinities of maingroup-element hydrides.
abstract: We have carried out an extensive exploration of gas-phase alkyl cation affinities (ACA) of archetypal anionic and neutral bases across the periodic system using zeroth order regular approximation-relativistic density functional theory at BP86/QZ4P//BP86/TZ2P. ACA values were computed for the methyl, ethyl, i-propyl and t-butyl cations and compared with the corresponding proton affinities (PA). One purpose of this work is to provide an intrinsically consistent set of values of the 298 K ACA of all anionic (XH (n-1)(-)) and neutral bases (XH(n)) constituted by maingroup-element hydrides of groups 14-17 and the noble gases (group 18) along the periods 1-6. Another purpose is to determine and rationalize the trend in affinity for a cation as the latter varies from proton to t-butyl cation. This undertaking is supported by quantitative bond energy decomposition analyses. Correlations are established between PA and ACA values.
authors.affiliation: Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM), Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruiz
authors.forename: R Joshua
authors.initials: RJ
authors.lastname: Mulder
authors.forename: Célia
authors.initials: C
authors.lastname: Fonseca Guerra
authors.forename: F Matthias
authors.initials: FM
authors.lastname: Bickelhaupt