Physical-chemical studies on putrescine (butane-1,4-diamine) and its solutions: Experimental and computational investigations

The results of Fourier Transform Infrared absorption and Raman spectroscopy studies are reported for solid and liquid neat butane-1,4-diamine (DAB) and for the molecule in different solvents. Ab initio molecular dynamics and static calculations are reported in the work as an interpretative tool for the measurements and provide an analysis of the relative population of DAB conformers, both in vacuo and in the liquid phase. X-ray diffraction data for liquid DAB are presented to further consolidate the interpretation of the conformation and structure of the biomolecule in the liquid phase. The study of DAB in polar solutions suggests a high level of structuring of the molecules in the liquid, as a consequence of the effect of solvent on the molecular charge distribution.