Infrared and Raman analyses of the halogen-bonded non-covalent adducts formed by α,ω-diiodoperfluoroalkanes with DABCO and other electron donors

Supramolecular Route to Fluorinated Coatings: Self-Assembly Between Poly(4-vinylpyridines) and Haloperfluorocarbons

“…In fact, m CH blueshifts similar to those of IR spectra are observed and the C±I bond vibration (at 277 cm ±1 in pure 3a) undergoes a highly diagnostic redshift on complex formation. [26] In agreement with the binding site saturation stoichiometry proposed through IR analyses, complexes 5a, with N/I ratios larger than 1:1, all gave the same redshift for the C±I absorption, this shift being the largest obtained value. In the P4VP-(DIPO) 1.0 complex, therefore, both the electron donor and acceptor sites are all involved in halogen-bonding formation.…”

Highly Interpenetrated Supramolecular Networks Supported by N⋅⋅⋅I Halogen Bonding

“…The spectra of the adducts 6-9 are approximately the sum of the spectra of the precursors; the band shifts and intensity changes as compared with the spectra of the pure starting modules are perfectly consistent with electron donation from the nitrogen atoms in 1 to the iodine atoms in 2-5. As an inevitable consequence of the n!s* nature of the XB connecting the modules, [22] some bands of the electrondonor species 1 are blueshifted while some bands of the electron-acceptor modules 2-5 are redshifted upon adduct formation. For instance, the ñ C-H absorption of pure tetrapyridyl pentaerythritol 1 at 3025 cm À1 becomes less intense in adducts 6-9 and is shifted to 3041-3044 cm À1 in adducts 6-8 and to 3035 cm À1 in 9.…”

Halogen Bonding with Dihalogens and Interhalogens

“…These are readily observed, however, in complexes of the dihalogens. The C-X and halogen bond vibrations are also difficult to identify unambiguously in the organoiodines, and vibrational spectroscopy has not been commonly used in the study of such complexes [10]. This is not the case with X 2 and XY, where valuable structural information is readily obtained [11,12].…”