LTN-type zeolite framework as an interpenetrating net of KFI- and SOD-type parts homeomorphic to cuprite, Cu2O

摘要

The complex LTN-type zeolite framework is described as consisting of two interpenetrating parts in order to understand the connectivities of their underlying nets. Both parts are homeomorphic to diamond-type tetrahedral frameworks, arranged in principle in the same manner as the two interpenetrating frameworks in cuprite, Cu2O. However, in cuprite the two frameworks are identical, while in the LTN-type framework one is made up of two kinds of truncated octahedra (toc units) and can be described as one half of the sodalite-type framework (SOD). The other consists of large cages, so-called truncated cubo-octahedra (grc units) connected by hexagonal prisms (double six-rings) and corresponds to one half of the KFI-type framework. Neither of the sub-frameworks has so far been observed in any other zeolite topology. The two sub-frameworks of SOD and KFI types in the interpenetrating LTN-type framework are models for very open interrupted frameworks, which possibly could be synthesized separately in a pure form. Their framework density would be 7.6 T atoms per 1000 angstrom(3) if they could be prepared as aluminosilicates.