Guest/Host Interactions in High Silica Zeolite Synthesis:  [5.2.1.0^2.6]Tricyclodecanes as Template Molecule

Abstract

Zeolite synthesis results for the use of a family of related quaternary ammonium derivatives of tricyclodecane hydrocarbons as structure-directing agents are described. The work continues our interest in how rigid polycyclic hydrocarbons, as charged derivatives, occupy space in developing guest/host zeolite lattices. The zeolite product chemistry was probed as to the three-dimensional structures formed, particularly in relation to synthesis variables like boron substitution for silicon in the lattice, OH-/SiO2 reactant concentration, and the stereochemistry of the polar substituents off the tricyclo[5.2.1.02.6]decane hydrocarbon frame; all three factors were found to have an impact on the zeolites which crystallized. Some correlations were also studied for how these factors influenced the size and architecture of the resulting pore systems. Monte Carlo methods were also applied to calculate favorable docking energies for geometry-optimized organo-cations placed in the host lattices.

Open-Framework Inorganic Materials

“…[250] The scope of this field is not limited by nature itself, since the number of hypothetical, three-dimensional framework topologies is infinite, [251] but it is limited by the creativity of the synthetic chemist. New preparative strategies continue to appear, such as the use of different solvent systems, [49,50] the synthesis of new organic template molecules, [252] and the construction of open frameworks from molecular building blocks (Section 8). The use of computational methods in the design of organic templates for the synthesis of novel architectures is also of great interest.…”

New Insights into the Role of Amines in the Synthesis of Molecular Sieves in Ionic Liquids

“…Our findings are in accord with the recent work of Gómez-Hortigüela et al [39] for the synthesis of the AFI structure in supramolecular solution in which minor benzylpyrrolidine molecules are required for the formation of the initial nuclei, then the crystal growth process can occur through occlusion of single molecular SDA units. Zones et al [10][11][12] also proposed a new zeolite synthesis system in which a minor SDA is used to selectively specify the nucleation product, then a larger amount of other amines is used to provide pore-filling agents for the crystal growth. So, our work further provides evidence for the importance of SDAs in the nucleation with regard to the phase selectivity.…”

Synthesis Approaches

“…By using Diels-Alder chemistry, Zones et al [107] prepared a family of tricyclodecane derivatives to make MOR, MTW, CON, SSZ-31, and SSZ-37 zeolites. Calabro et al [100] used the Diels-Alder reaction to prepare the N,N,N ,N -tetraalkyl-exo,exo-bicyclo[2.2.2]oct-7-ene-2,3:5,6-dipyrrolidinium cation, which was used to prepare MCM-68 (MSE), the first zeolite to have an intersecting 12 × 10 × 10 ring channel system [108].…”