Synthesis and characterization of montmorillonite clay intercalated with molecular magnetic compounds

In this work montmorillonite (MMT) clay, whose matrix was modified with an ammonium salt (hexadecyltrimethylammonium bromide - CTAB), was employed as an inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange: a nitronyl nitroxide derivative 2-[4-(N-ethyl)-pyridinium]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (p-EtRad(+)) and two binuclear coordination compounds, [Ni(valpn)Ln](3+), where H(2)valpn stands for 1,3-propanediyl-bis(2-iminomethylene-6-methoxy-phenol), and Ln=Gd-III; Dy-III The pristine MMT and the intercalated materials were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and magnetic measurements. The X-ray diffraction data analysis showed an increase of the interlamellar space of the intercalated MMT, indicating the intercalation of the magnetic compounds. Furthermore, the magnetic properties of the hybrid compounds were investigated, showing similar behavior as the pure magnetic guest species. (C) 2015 Published by Elsevier Inc.