Extensive theoretical investigation: influence of the electrostatic environment on the I3 −···I3 − anion–anion interaction

Crystal structure of 1,10-phenanthrolindiium bis(triiodide) monohydrate, C12H12I6N2O

“…0.4 Åw as observed in ac ompound where both hydrogen bonding and I×××Iinteractions were found [10].Itisworth mentioning that the distortions of both I 3 -ions from point group symmetry D ¥h ,inthe title compound, are caused by the asymmetry of their environments and different strength of interactions in which they are involved. The strengths of those interactions are consistent with the variation of charges on the terminal and central iodine atomsi nI 3 - [11,12]. The C×××Ia nd C-H×××Ic ontacts are mainly responsible for the deviation from linearity of the (I-I-I) -ions, whereas mostly the I×××Icontact of 3.8980(5) Å(all shorter than the sum of the van der Waals radii for relevant atoms [13,14]) causes the asymmetry of the I-I bond lengths.…”

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

“…This agrees with a theoretical investigation by Åqvist and Hansson [6], who showed that the linear response approximation with respect to the electrostatics of the solute and the solvent utilized in the continuum electrostatic theory is valid for monovalent ionic compounds and, to a lesser degree, for dipolar compounds. Our results [3] suggested that a solvent with a dielectric constant of 20 would lead to a DE S of $40 kcal/mol, which would be sufficient to change the I 3 -Á Á ÁI 3 -interaction to attractive from being repulsive in the gas phase. We also postulated that n-methyl-formamide (NMF) as a solvent described by an electrostatic continuum could be utilized as a pseudocrystalline environment in order to study the I 3 -Á Á ÁI 3 -interaction energy.…”

“…We are interested in describing the interactions between triiodide ions (I 3 -), which we have shown do not exist in the gas phase, as might be expected due to electrostatic repulsion, although they are present in experimental crystal structures [3]. In order to explain this phenomenon, we need to model the interaction in the solid state, which becomes an intractable problem even when using computational methods such as DFT.…”

“…As a first step in this process [3], we studied the I 3 -Á Á ÁI 3 -interaction in solution (described using the polarizable continuum model) and concluded that the repulsive electrostatic component of the I 3 -Á Á ÁI 3 -interaction energy decreases as the interaction between the I 3 -ion and the surrounding electrostatic continuum increases.…”

Antibacterial and Antifungal Activity of the Triiodide [Na(12-Crown-4)₂]I₃ on the Pathogens <em>Escherichia coli, Streptococcus pyogenes, </em><em>Streptococcus faecalis, </em><em>Bacillus subtilis, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans </em>

“…Anion-π-interactions in combination with electron-poor, polarized salts showed a stabilizing effect of polyiodides in the solid state [8]. The I-I-distances in the I3 --anion and the I3 -•••I3 --interactions in its dimers were investigated in the gaseous phase and in theoretical studies [9]. Further importance is in the use of cations as stabilizing factor in polyiodide structures, their effect on halogen bonding and asymmetry in triiodides [10].…”