Supertetrahedral Sulfide Crystals with Giant Cavities and Channels

Abstract

Although aluminosilicates and metal phosphates can form porous open-framework materials such as zeolites, sulfide analogs usually form high-density phases because of the relatively small tetrahedral angle at sulfur atoms. One strategy to overcome this limitation is to use tetrahedral clusters as the building blocks to achieve porous sulfide-based networks. The preparation and crystal structures of two indium sulfide open frameworks (ASU-31 and ASU-32) built of supertetrahedral clusters around organic template and water guests are described. ASU-31, based on the sodalite-tetrahedrite network, contains cavities 25.6 angstroms in diameter, and ASU-32, based on the tetragonal CrB4 network, contains channels with a minimum diameter of 14.7 angstroms. The organic cations can be completely exchanged with sodium ions in aqueous solution at room temperature without degradation of the crystals.

Nanohedra: Using symmetry to design self assembling protein cages, layers, crystals, and filaments

“…Layers and solids with large pores might also be useful as molecular sieves. Porous materials have been fabricated from silicates and more recently from metal sulfides and metal phosphates, but it has been difficult to exceed a pore diameter of roughly 1.4 nm (11,13). Twoand three-dimensional nanohedral protein materials could have precisely defined pore sizes in the 5-nm to 20-nm range.…”

“…These materials fall into different architectural classes, such as compact clusters (2), hollow shells (3)(4)(5) and tubes (6 -8), twodimensional layers (9,10), and nanoporous materials (11)(12)(13). In recent years, a wide variety of chemical building blocks and synthetic strategies have been investigated.…”

Open-Framework Inorganic Materials

“…Furthermore, the very recently discovered indium sulfides, ASU-31 and ASU-32, which are large-pore systems based upon linked supertetrahedra containing 10 [InS 4 ] units, exhibit interesting ionexchange properties. [219] …”

Mesostructured Non-Oxidic Solids with Adjustable Worm-hole Shaped Pores: M-Ge-Q (Q = S, Se) Frameworks Based on Tetrahedral [Ge4Q10]4- Clusters

“…A recent exciting development toward producing well-defined mesostructured materials is the discovery of ASU-32, a novel indium sulfide that features pore diameters of~14.5 . [16] We describe here a new class of mesostructured M/Ge 4 Q 10 (M = Zn, Cd, Hg, Co) based frameworks with large, adjustable, surfactant-filled worm-hole like tunnels. We have employed the electrostatic self-assembly approach developed at Mobil, [1] using a mainly aqueous route (with methanol or ethanol added), and employing suitable cationic organic surfactant species, to form mesoporous metal sulfide frameworks.…”

“…We have employed the electrostatic self-assembly approach developed at Mobil, [1] using a mainly aqueous route (with methanol or ethanol added), and employing suitable cationic organic surfactant species, to form mesoporous metal sulfide frameworks. These materials are formulated as (RNMe 3 ) 2 [MGe 4 Q 10 ] (Q = S, Se) and will be referred to as C n MGeQ (n = 12, 14,16,18). While this manuscript was in preparation, Ozin et al reported on the non-aqueous synthesis of mesostructured metal germanium sulfides from [Ge 4 S 10 ] 4± clusters.…”