Uses of i.r. spectroscopy in identifying ZSM zeolite structure

The study of i.r. lattice vibrational bands (400–1200cm–1) for different types of zeolites with different particle sizes indicates, when synthesising a ZSM-type zeolite, that (i) the presence of a band at ca. 550 cm–1 in addition to the one at 450 cm–1 shows that ZSM-type zeolite, crystallites may have been formed, even if X-ray diffraction shows nothing, and (ii) the absence of the 550cm–1 band unambiguously shows that such a zeolite has not been formed.