FT-IR and FT-Raman spectroscopic investigations of adsorption of 2-aminopyridine on natural and ion-exchanged bentonites

The adsorption of 2-aminopydine (2AP) on natural and ion-exchanged bentonit es (Mn-, Fe-, Co- or Ni-bentonite) have been investigated using IR and Rama n Spectroscopy. The intercalation of 2AP within natural and ion-exchanged b entonites has been shown by X-ray diffraction to increase the interlayer sp acing. Vibrational spectroscopy indicates that intercalated 2AP molecules a re coordinated to Lewis acid sites or exchangeable cations (directly or ind irectly through water bridges). It is concluded that ring nitrogen, not the amino nitrogen is involved in coordination. Moreover amino group hydrogens are found to be involved in hydrogen bonding interaction with water molecu les (NH ... OH2). (C) 1999 Elsevier Science B.V. All rights reserved.