Using InCl vapor to ion exchange indium into zeolite Na–X. II: A single crystal structure containing (In8Cl8)16+, In57+–Cl−–In57+, and In+

Anhydrous vapor phase ion exchange (VPIE) using InCl(g) had been used to introduce indium ions into zeolite Na92–X (FAU, Si/Al = 1.09); the product was In14+(In57+)4Na50+–X. Treatment of Na92–X with a lower vapor pressure of InCl(g) at lower temperatures has now yielded In6.4+(In8Cl8)1.7316+(In10Cl)1.013+Na45.6+–X; Cl− ions were retained and cationic InnClmp+ clusters have formed. Its structure was determined using single-crystal crystallography with synchrotron X-radiation and was refined in the space group Fd3¯ (a = 24.890(1) Å) to the final error index R1 = 0.066. In8Cl816+ clusters center and extend out of 22% of the sodalite cavities. Each consists of a tetrahedrally distorted In4Cl4 cube (In–Cl = 2.323(23) Å) with –In–Cl extending radially from each of its Cl− ions (the Cl–In–Cl distances are 2.302(17) and 2.406(14) Å, respectively). With Cl− ions and oxygen atoms of the zeolite framework, these indium ions, all In3+, have octahedral and trigonal bipyramidal coordination, respectively. In57+ cationic clusters center another 25% of the sodalite cavities. In57+ is a centered tetrahedron with In–In = 2.745(8) Å; each terminal atom bonds to three framework oxygen atoms of a double 6-ring with In–O = 2.150(5) Å and O–In–O = 105.1(3)°. One terminal atom of each In57+ cluster also bonds to a Cl− ion at site I, which in turn bonds linearly to a terminal atom of another In57+ cluster. In this way the In57+ units link together in pairs to give In10Cl13+. The remaining indium cations, 6.4 In+ per unit cell, are in the sodalite cavities. Most of the Na+ ions, 25.1 per unit cell, complete the filling of the single 6-rings; the remainder are at 12-ring sites.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Anhydrous vapor phase ion exchange using InCl(g) into FAU. ► Formation of large intrazeolitic clusters of InnClmp+. ► A view of an intermediate (non-equilibrium) stage of a VPIE process. ► A precise structure using single-crystal methods and synchrotron radiation.