Zn+ cations, probable Tl4Zn12 and Tl6 clusters, and zeolite desilication (less likely dealumination):: Crystallographic study of the incomplete reaction of Zn vapor with Tl+-exchanged zeolite X

The products of the reaction of Zn vapor with fully dehydrated fully Tl+-exchanged zeolite X (Tl92Si100Al92O384 per unit cell) at 450 degrees C (crystal 1, a(0) = 24.825(3) Angstrom, Tl62+Zn30+Si100Al92O384. 2Tl(0), 15Zn(0)) and 500 degrees C (crystal 2, a(0) = 24.950(4) Angstrom, Tl18+Zn462+Si98Al94O384. 4SiO(4)(4-)) have been studied by single-crystal X-ray diffraction in the cubic space groups Fd (3) over bar m and Fd (3) over bar, respectively. In crystal, 30 Tl+ ions were reduced by Zn(g) and replaced by Zn+ ions (18 are found at site I' and 12 at site II'). This is the first report of the monatomic cation Zn+. Some of the product Tl atoms and additional Zn(g) atoms were captured by some of the remaining site-II Tl+ ions possibly to form (sparsely) (Tl4+Zn12Tl40)-Tl-0 clusters Of symmetry;(4) over bar 3m at supercage centers. This cluster has a central Tl-4 tetrahedron surrounded by 12 Zn atoms, surrounded by four Tl+ ions (a third shell), all in a cubic closest-packed arrangement. Other Tl+ ions have captured Zn atoms, perhaps to form smaller clusters. The Tl+ populations at the III' sites were unaffected by this reaction. In crystal 2, the desired redox reaction of Zn(g) with Tl+ has gone most of the way to completion. Almost all Tl+ ions at sites I' and II, and 12 of the 28 at III' sites, have been replaced by Zn2+ at sites I', II', and II. An orthosilicate ion (aluminate less likely) is found at the centers of half of the sodalite units. Each orthosilicate oxygen bridges between a Zn2+ ion at site I' (2.11 Angstrom) and another at site II' (2.17 Angstrom) and lies in its Zn2+, Zn2+, Si4+ plane. A formally neutral octahedral Tl-6 cluster, supported by coordination to Zn2+ cations, appears to center some sodalite cavities.