Topochemical reactions of amines and amides with titanium and vanadium oxychlorides.

Abstract

The intercalation of primary, secondary, tertiary, and aromatic amines into layered TiOCl have been investigated by a variety of methods. The intercalation reaction does not appear to be a redox process. A key step for intercalation of amines into host TiOCl is proposed to be a coordination via nitrogen lone electron pair to Ti$\sp{3+}$ metal centres. Subsequent substitution of the interlayer chloride ions of TiOCl by the amine molecules is strongly dependent on the properties of the organic compounds and their ability to form ammonium salts. Based on X-ray diffraction, fluorescence, elemental analysis and thermal analysis, a model for the interaction of amines with TiOCl is proposed. The intercalation of primary, secondary, and tertiary amides into TiOCl and VOCl have been studied. A redox intercalation process is ruled out by using variety of amides with a range of redox potentials. The proposed interaction of intercalated amides with the host is different from that of amines and may dominated by formation of hydrogen bonds between the amides protons and Cl ions of the host.