Crystallization of zeolite ZSM-39 studied by 13C and 29Si magic-angle spinning nuclear magnetic resonance spectroscopy

Abstract

13 C CP MAS NMR, 29Si MAS NMR and XRD have been used to study the crystallization of zeolite ZSM-39 in the tetramethylethylenediamine (TMEDA)–SiO2–H2O system. With the formation of the precursor from SiO2 species surrounding TMEDA followed by nucleation, the 13C chemical shift of the —C2H4— group moves progressively to higher field. This indicates that one molecule of TMEDA is shared by two neighbours of the [51264] cage and that the —C2H4— group of TMEDA interacts strongly with oxygen atoms located at the 6-ring window between the two cages.