Solid-state intercalation of 4,4′-bipyridine and 1,2-di(4-pyridine)ethylene into the interlayer spaces of Co(II)-, Ni(II)- and Cu(II)-montmorillonites

Intercalation of two diimines, 4,4′-bipyridine (4BPY) and 1,2-di(4-pyridine)ethylene (DPE), into the interlayer spaces of cobalt(II)-, nickel(II)- and copper(II)-montmorillonites by solid–solid reactions was investigated. The successful intercalation of these compounds through coordination to the interlayer exchangeable cations was confirmed by powder X-ray diffraction, infrared spectroscopy, elemental (CHN) analysis, and thermal analysis of the products. The presented solid-state intercalation of bidentate bridging ligands and in situ complex formation in the interlayer spaces of montmorillonite is a feasible way to prepare clay-coordination polymer-intercalation compounds, which cannot be obtained in conventional ion exchange reactions.