Single crystal growth,morphology, and structure of ZSM-39 and its variation CF-4

Single crystals of ZSM-39 and its variation CF-4 were crystallized with various habits. The crystals had a size up to 450 m and were hydrothermally grown over a period of 8 to 72 days from a gel system consisting of amine-alcohol-SiO₂–H₂O at 200°C. The amines used were MA (methylamine), TMEDA (N,N,N,N-tetramethylenediamine), TMAOH, TEAOH, isopropylamine,tert-butylamine, hexahydropyridine,n-propylamine, andN,N-dimethylethanolamine. The alcohols used were glycerine, ethylene glycol, and 1,3-propanediol. The highest quality crystals of ZSM-39 were grown in a system of MA–SiO₂–H₂O, and CF-4, in the MA-glycerine-SiO₂–H₂O system. The optical properties of these crystals were observed and crystal structures were measured from both powder and single crystal diffraction data.