Novel materials based on organic–tungsten oxide hybrid systems I: synthesis and characterisation

Novel layered materials based on diaminoalkane–tungsten oxide have been synthesised and characterised. Results from X-ray diffraction (XRD) indicate these materials are layered with the corresponding interlayer spacing governed by the diaminoalkane chain length. Infrared spectroscopy (IR) studies reveal differences in the structure of the terminal amine groups, with diaminoethane–tungsten oxides having NH2 terminal groups while the longer amines are mostly NH3+ terminated. Consequently, two different decomposition temperature regions are observed in thermal gravimetric analysis (TGA) for this hybrid system. The intercalation of amines into the tungsten oxide framework also appears to increase the band-gap energy (Eg) as compared with WO3, but no difference in Eg was observed among the diaminoalkane–tungsten oxides, indicating that the oxide layers are electronically decoupled.