Electrostatic surface potential analysis of the I3- ion in the gas phase, the condensed phase and a novel extrapolation to the solid state

A theoretical investigation focusing on the dependence of selected parameters on the Electrostatic Surface Potential (ESP) of the I-3(-) ion and the I center dot center dot center dot I interaction between two such ions in the gas phase and chloroform, ethanol, water and n-methyl-formamide solutions is described here. The ESP analyses, performed utilizing the B3PW91, TPSS-D2, PBE-D2, B97D and MP2 methods, show linear relationships between the V-S,V-MAX value and the relative permittivity of the surrounding solvent environments, the stabilization of the triiodide species and the I center dot center dot center dot I interaction energy between two triiodide ions in the solvents. The V-S,V-MAX value of an I-3(-) ion within a model crystal where the surrounding atoms are replaced by point charges follows a similar trend. On this basis, a method to determine the stabilization energy of an ion within a crystalline lattice, and thus the interaction energy between species with like charges that is attractive in the solid state but repulsive in gas phase, is proposed. (C) 2016 Elsevier B.V. All rights reserved.