Symmetrical and Topological Self-Assembly Code of the Crystalline Structure of a New Aluminosilicate Zeolite ISC-1 from Templated t-plg Suprapolyhedral Precursors

Abstract

In 2008, V.Ya. Shevchenko and S.V. Krivovichev built the zeolites series related to paulingite based on the inorganic gene concept and predicted a new zeolite named ISC-1 (Institute of Silicate Chemistry-1) [1]. The structure and composition of ISC-1 are described in detail in [2]. The found chemical formula of the new zeolite ISC-1 is Na₁₄K₂₄Al₃₈Si₂₀₂O₄₈ · nH₂O. Further research on the principles of assembly of zeolites and prediction of another previously unknown zeolite, ISC-2 (Institute of Silicate Chemistry-2), and the conditions of its formation are presented in [3–5]. The combinatorial-topological analysis of the crystal structure of the new aluminosilicate zeolite ISC-1 with cubic cell parameters а = 25.039 Å, V = 15 699 ų, and spatial group Im$\bar {3}$m is performed by computer-based methods (ToposPro software package) [6]. The topological type of the framework composed of bonded Т–(Si,Al)O₄ tetrahedra is characterized by a combination of polyhedral tilings: t-grc (48 T-atoms), t-pau (32 T-atoms), t-plg (30 T-atoms),t-opr (16 T- atoms), and t-oto (16 T- atoms). A framework-forming precursor for zeolites of 30 T-tetrahedra, which corresponds to the t-plg tile and contains an organic template Me₂-DABCO (N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane), is established by the complete decomposition of the 3D atomic lattice into cluster structures. t-plg nanoclusters with the symmetry g = $\bar {3}$m are characterized by 4-, 6-, and 8-rings and the n-hedral symbol [4⁶. 6². 8⁶]. Na-spacers statistically occupy neighboring positions in the 8-ring and between the 4‑rings of the neighboring t-plg clusters. The basic 3D lattice type indicative of t-plg clusters center-of-gravity positions correspond to a simple cubic lattice with CN = 6. The self-assembly code of the 3D structure from complementary bonded nanoclusters-precursors is simulated in its entirety: primary chain → microlayer → framework. The doubled distance between t-plg clusters centers corresponds to the cubic cell translation vector a = 25.039 Å.