K-paracelsian (KAlSi3O8·H2O) and identification of a simple building scheme of dense double-crankshaft zeolite topologies

[摘要] During screening of the phase space using KOH and 1-methyl-4-aza-1-azoniabicyclo­[2.2.2]octane hydroxide (1-methyl-DABCO) under hydrothermal zeolite synthesis conditions, K-paracelsian was synthesized. Scanning electron microscopy, energy dispersive X-ray spectroscopy and ex situ powder X-ray diffraction analysis revealed a material that is compositionally closely related to the mineral microcline and structurally closely related to the mineral paracelsian, both of which are feldspars. In contrast to the feldspars, K-paracelsian contains intrazeolitic water corresponding to one molecule per cage. In the case of K-paracelsian it might be useful to consider it a link between feldspars and zeolites. It was also shown that K-paracelsian can be described as the simplest endmember of a family of dense double-crankshaft zeolite topologies. By applying the identified building principle, a number of known zeolite topologies can be constructed. Furthermore, it facilitates the construction of a range of hypothetical small-pore structures that are crystallo-chemically healthy, but which have not yet been realized experimentally.

[学科分类] 数学（综合）

[关键词] K-PARACELSIAN;DENSE DOUBLE-CRANKSHAFT ZEOLITE TOPOLOGIES;STRUCTURE REFINEMENT;CRYSTAL ENGINEERING;INORGANIC POROUS SOLIDS;MICROPOROUS MATERIALS