Abstract

The electrophilicity index is analyzed within the framework of spin-polarized density-functional theory. In this context, constrained philicities, ωN ≡ (μN) 2 (2 ηNN), are introduced in order to define the capability of a system to acquire or donate electrons in a process at constant spin number. The spin-philicity/spin-donicity indices, ωS± ≡ (μS±) 2 (2 ηSS), are examined and rationalized here as the philicity of a given system to change its spin-polarization state, as being defined through the spin potential μS and spin hardness ηSS for a process at constant number of electrons. The local extension of these indices has been also outlined and numerical results have been discussed on the analysis of the electrophilic nature of some simple carbene systems both in the singlet and triplet states. © 2006 American Institute of Physics.