INTERCALATION STUDIES OF SEVERAL LAYERED LANTHANIDE OXYCHLORIDES WITHPYRIDINE

A series of new intercalation compounds of the layered lanthanide oxyc hlorides, LnOCl (Ln = Ho, Er, Tm and Yb), with pyridine has been succe ssfully obtained at both room and high temperature (85-degrees-C). The intercalated pyridine stoichiometries (x) in the (py)xLnOCl compounds , determined by thermal gravimetric analysis, are independent of the r eaction temperature and time after 2 weeks with the (py)xErOCl and (py )xYbOCl, but are affected by the reaction temperature and time with th e (py)xHoOCl and (py)xTmOCl. An average interlayer expansion of approx imately 5 angstrom between the LnOCl layers upon pyridine intercalatio n suggests that the pyridine ring is oriented perpendicular to the hos t layers. The pyridine species inserted between the host layers are ne utral pyridine molecules. The presence of water in pyridine leads to t he pyridinium ion that also intercalates and has been identified by IR spectroscopy.