IR, Raman and surface-enhanced Raman study of desferrioxamine B and its Fe(III) complex, ferrioxamine B

IR, Raman and surface-enhanced Raman scattering (SERS) spectroscopies were employed for the structural investigation of the chelator desferrioxamine B and its Fe(III) complex, ferrioxamine B. Comparing the FT-IR absorptions of desferrioxamine B and ferrioxamine B, the structural changes due to the Fe(III) chelation were clearly evidenced by spectral analysis. Despite the intense CO stretching vibration in the FT-Raman spectrum of desferrioxamine B, the FT-SERS spectrum is dominated by a strong CN stretching vibration, indicating a delocalization of the N lone pair of electrons and the formation of the CN bond in the hydroxamate groups. The desferrioxamine B and ferrioxamine B molecules are adsorbed to the silver colloidal particles through the O atoms of the hydroxamate functional groups, with similar orientation with respect to silver surface.