*2.7. Fourier-Transform Infrared Spectra*

Fourier-transform infrared spectra (FTIR) were recorded with an attenuated total reflectance (ATR) accessory diamond crystal using an Invenio R FTIR spectrometer (Bruker). FTIR spectra were recorded within the wavenumber range from 4000 cm−<sup>1</sup> to 400 cm−<sup>1</sup> at 2 cm−<sup>1</sup> resolution. In order to correctly subtract the background and, hence, obtain less noisy spectra, the solvent (0.9% NaCl water solution) was used at room temperature for the background measurement.
