Fig. 1.

Starting materials for VPT and respective products. Structures of initial zeolites are porous frameworks composed of layers (blue tetragons) and connecting D4R units (orange squares). Vapour of HCl (blue on treatment scheme of the VPT method) interacts with solid zeolite resulting in structural transformation accompanied by leaching of Ge atoms probably as GeCl₄. Respective D4R units can be either reconstructed to S4Rs or decomposed. Final structures obtained via conventional ADOR and VPT rearrangement of the parent zeolites (IWW, UOV and UTL) are different due to the difference in layers porosity, thus in the interlayer species diffusion rate