Formation of coordination compounds with aniline in the interlayer space of Ca2+-, Cu2+- and Fe3+-exchanged montmorillonite.

The influence of Ca²⁺-, Cu²⁺- and Fe³⁺-exchanged montmorillonite (MMT) on the type of interaction with aniline in the interlayer space of MMT has been studied by means of X-ray powder diffraction and infrared spectra. Results of X-ray diffraction showed that aniline was successfully intercalated into the interlayer space of MMT. Based on IR spectra evaluation, aniline was indirectly coordinated through a water-bridge in Ca²⁺- and Fe³⁺-MMT and it was indirectly coordinated through a water-bridge as well as protonated in Cu²⁺-MMT (the spectrum of protonated aniline showed deformation and changes in the NH⁺³ absorption at approximately 1521 cm⁻¹). It is important to point out that Cu²⁺-MMT indirect coordination and protonation occur simultaneously. [ABSTRACT FROM AUTHOR]