Chiral recognition and complexation behaviour of beta-CyD vs L- and DL-serine by FTIR-ATR spectroscopy

Solid inclusion complexes of the amino acid (D,L)-serine and (L)-serine with b-cyclodextrin (b-CD) have been investigated by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR), in order to put into evidence the effects of chiral properties on the complexation process. The spectral changes induced by complexation in the vibrational spectra of serine have been monitored in the 600-4000 cm-1 range, recognizing the functional groups taking part in the ''host-guest'' interactions. Again, the quantitative analysis, vs. T, of the C@O stretching vibration, by means of a best-fit procedure, furnished the enthalpy changes associated to the binding of serine with beta-CD in solid phase. The most stable inclusion complex turned out to be the one formed by (L)-serine, and then (D,L)-serine.