The consideration of the disposition of minima of electron density and electrostatic potential along the line between non-covalently bound atoms in systems with Hal⁻···CH₃–Y (Hal⁻ = Cl, Br; Y = N, O) fragments allowed to prove that the carbon atom in methyl group serves as an electrophilic site provider. These interactions between halide anion and carbon in methyl group can be categorized as the typical tetrel bonds. Statistics of geometrical parameters for such tetrel bonds in CSD is analyzed. It is established that the binding energy in molecular complexes with tetrel bonds correlate with the potential acting on an electron in molecule (PAEM). The PAEM barriers for tetrel bonds show a similar behavior for both sets of complexes with Br⁻ and Cl⁻ electron donors.

A number of new solid polyiodides of thia- and oxa-zinoquinolinium derivatives have been characterized using a combined approach of Raman spectroscopy and periodic 3D calculations of the Raman intensities. Various cation–anion ratios, including tri- and polyiodides of the complex structure [I₃⋯I₂]⁻, have been studied. For the oriented single crystal containing the [I₃⋯I₂]⁻ fragments, the polarized Raman spectra and the angular dependency of the band intensities on crystal rotation have been obtained. These techniques have allowed us to get new information on the spatial organization of the intermolecular interactions of iodine in polyiodide-anion chains. They have also shown perspectives on the geometrical characterization of complex polyiodides using Raman spectroscopy.