Some topochemical reactions based on the mox lamellar oxychlorides of transition metals

Abstract

Intercalation of molecules and alkali metals are possible in lamellar transition metal oxyhalides. Intercalations in such lattice depend on different factors, which are the rigidity of the lattice and the stability of the +3 oxidation state of the metal. This structure leads also to irreversible topochemical reactions involving the substitution of the chlorine atoms by organic molecules possessing one or two nucleophilic groups. In the first case simple grafting reactions occur giving new layers compounds as FeOOCH 3 or FeOOCOCH 3 by example. In the second one, if we choose rigid organic molecules we realize double grafting or pillaring reactions KRK + 2FeOCl → 2KCl + FeOROFe. A new and interesting type is based on the following process 2FeOCl + K 2Fe(CO) 4 → 2KCl + (FeO) 2Fe(CO) 4. Chlorine layers are removed as potassium halide and simultaneously tetrahedral anionic groups are added.