Gas-phase hydride affinities of neutral molecules

In this review we report the hydride affinities for neutral molecules. The hydride affinity is defined as the enthalpy of reaction for the dissociation of RH- to yield R+ H-. These important thermodynamic quantities, however, are not often measured experimentally. Instead, hydride affinities are typically calculated from thermochemical cycles. We show several methods for calculating hydride affinities and have compiled a list of hydride affinities for a large number of molecules. In addition to reporting hydride affinities for many common compounds, this review also details the hydride affinities of reactive intermediates, including radicals, carbenes, biradicals, and triradicals. The hydride affinities reported in this review are interpreted on the basis of thermochemical data and simple molecular orbital pictures. (C) 2006 Elsevier B.V. All rights reserved.