[en] Within the context of spin polarized conceptual density functional theory, the spin polarized linear response functions are introduced both in the [N, N_s] and [N_α, N_β] representations. The mathematical relations between the spin polarized linear response functions in both representations are examined and an analytical expression for the spin polarized linear response functions in the [N_α, N_β] representation is derived. The spin polarized linear response functions were calculated for all atoms up to and including argon. To simplify the plotting of our results, we integrated χ(r, r′) to a quantity χ(r, r^′), circumventing the θ and ϕ dependence. This allows us to plot and to investigate the periodicity throughout the first three rows in the periodic table within the two different representations. For the first time, χ_αβ(r, r^′), χ_βα(r, r^′), and χ_SS(r, r^′) plots have been calculated and discussed. By integration of the spin polarized linear response functions, different components to the polarisability, α_αα, α_αβ, α_βα, and α_ββ have been calculated

[en] Generalized hardness and softness reactivity kernels are defined within a spin-polarized density-functional theory (SP-DFT) conceptual framework. These quantities constitute the basis for the global, local (i.e., r-position dependent), and nonlocal (i.e., r and r^'-position dependents) indices devoted to the treatment of both charge-transfer and spin-polarization processes in such a reactivity framework. The exact relationships between these descriptors within a SP-DFT framework are derived and the implications for chemical reactivity in such context are outlined

[en] Highlights: • Cryosolutions of C₆F₆ with dimethyl ether or trimethylamine are studied with FTIR. • Complex bands are assigned to lone pair···π complex using ab initio calculations. • Assignment of observed monomer and complex bands is given. • Using Van ‘t Hoff plots, complex enthalpies of both complexes are determined. The formation of complexes between hexafluorobenzene and the Lewis bases dimethyl ether, dimethyl ether-d₆, trimethylamine and trimethylamine-d₉ was investigated experimentally using FTIR spectroscopy on solutions of liquid krypton. Additional bands found in the spectra of mixtures were assigned to lone pair···π complexes using ab initio calculations at the MP2/aug-cc-pVDZ level. By constructing Van ‘t Hoff plots, experimental complexation enthalpies were determined of −6.0(6) kJ mol⁻¹ for the complex with dimethyl ether(-d₆) and −6.7(9) kJ mol⁻¹ for the complex with trimethylamine(-d₉). These values are in good agreement with calculated enthalpy values.

[en] In this theoretical and experimental study, the ability of carbonyl fluoride (COF_2) and carbonyl chloride fluoride (COFCl) to form noncovalent interactions with the Lewis base dimethyl ether (DME) is assessed. From ab initio calculations, two stable complexes are found for COF_2·DME, both formed through a lone pair⋯π interaction. FTIR measurements on liquefied noble gas solutions, supported by ab initio calculations, statistical thermodynamical calculations and Monte Carle Free Energy Perturbation calculations, show that a 1:1 lone pair⋯π bonded complex is found in solution, with an experimental complexation enthalpy of −14.5(3) kJ mol"−"1. For COFCl·DME three lone pair⋯π complexes, as well as a Cl⋯O halogen bonded complex, are found from ab initio calculations. Experimentally, clear complex bands for 1:1 lone pair⋯π complexes are observed, with an experimental complexation enthalpy of −11.4(2) kJ mol"−"1. Furthermore, indications of the presence of a small amount of the halogen bonded complex are also observed.