Reaction of Fully Indium-Exchanged Zeolite A with Hydrogen Sulfide. Crystal Structures of Indium-Exchanged Zeolite A Containing In₂S, InSH, Sorbed H₂S, and (In₅)⁷⁺

Abstract

Four single crystals of fully dehydrated, fully indium-exchanged zeolite A (Inca. 10−Si12Al12O48 or Inca. 10-A, colorless) were exposed to 0.5 atm of H2S for 3 h at 298, 373, 423, and 573 K for crystals 1 to 4, respectively. After evacuation at temperature followed by cooling to 294(2) K, the crystals were red, brown, yellow, and yellow, respectively. Their structures were determined by single-crystal X-ray diffraction techniques in the cubic space group Pm3̄m at 294(2) K (a = 12.083(3), 12.076(2), 12.094(2), and 12.094(2) Å; R1 = 0.069, 0.063, 0.065, and 0.060; R2 = 0.062, 0.058, 0.064, and 0.060 for crystals 1 to 4, respectively). The structures differ in the degree of sorption and/or reaction with H2S. Crystal 1 (In9.5H0.5−A(InSH)0.5(H2S)2.5) may be viewed as being an equimolar mixture of two kinds of unit cells with compositions In9−A(H2S)3 and In10H−A(InSH)(H2S)2. Unit cell 1 contains three H2S molecules stabilized as [(In)2(H2S)3]2+ in the large cavity and a tetrahedral (In5) n + cluster in the sodalite unit. Unit cell 2 contains unreacted (In3)2+ and an [(In)2(InSH)(H2S)2]2+ cluster with one InSH and two sorbed H2S molecules, all in its large cavity. Crystal 2 (In8.4H1.2−A(In2S)0.6(H2S)2) may similarly be viewed as being 40% In9−A(H2S)2 and 60% In8H2−A(In2S)(H2S)2. In9−A(H2S)2 has two sorbed H2S molecules in a [(In)2(H2S)2]2+ cluster, whereas In8H2−A(In2S)(H2S)2 has a [(In)2(In2S)(H2S)2]2+ cluster with one In2S and two sorbed H2S molecules in the large cavity. At higher reaction temperatures (423 and 573 K), the product crystals had less InHS and sorbed H2S. All crystals contain tetrahedral (In5) n + where n is likely to be 7. The number of sorbed H2S molecules decreases monotonically with increasing reaction temperature. In2S and InSH molecules were observed only in the large cavities, where more monopositive indium cations were initially available.

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

“…Considering the ionic radius of oxygen to be 1.32 Å [64], the radii of these In + ions is 2.54 À 1.32 = 1.22 Å. Although this is less than the radii assigned to In + in various indium halides (they range from 1.32 to 1.51 Å) [65][66][67], it agrees with those found in similarly prepared fully In-exchanged zeolites A, X, and Y, 1.254 Å [19,43,44] At site I' (In11) and site U (InU), two In 7þ 5 cations are found per unit cell in sodalite cavities (see Fig. 3).…”

“…The mean In-In bond lengths, 2.745(8) Å in this work and 2.763(7) Å in In,-Na,Cl-Y [20], are a little longer than those found in In 7þ 5 ) itself (2.668(6) to 2.694(8) Å [19,36,[43][44][45]74]. It appears that the bridging Cl À has caused the mean In-In bond length to increase.…”

“…Such a ratio had been seen several times before with values ranging from 3.2 to 4.3 in In-A [19,43,44], In-X [36,45], and In-Y [46]. Similarly, the ratio of the occupancies at Cl and InU is 2.0(5)/2.01(6) = 1.0(3), which may be more than that observed in In,Na,Cl-Y [20] (0.63 (15)), indicating some presence at Cl.…”

“…are In 3+ . In contrast, no In 3+ ions were found in fully indium-exchanged zeolites A [19], X [36,45], and Y [46], nor in the sorption complexes of zeolites A [43] and X [36] with H 2 S, of zeolite A with S [44], and of zeolite X with H 2 O [45]. Two reasons for this can be seen: (1) zeolite X is more ionic than Y and favors the formation of (can better stabilize) the highly charged In 8 Cl 16þ 8 cationic cluster, and (2) Cl À ions appear to bond particularly strongly to In 3+ .…”

Disproportionation of an Element in a Zeolite. I. Crystal Structure of a Sulfur Sorption Complex of Dehydrated, Fully Cd2+-Exchanged Zeolite X. Synthesis of Tetrahedral S44+ and n-S42+, Two New Polyatomic Cations of Sulfur

“…Well-defined clusters have been found in A, X, and Y type zeolites. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] By choosing different zeolites, nanoclusters with different structures and electronic properties can be built from the same sorbate. Attempts have been made to synthesize nanoclusters of semiconductors such as CdS, PbS, and PbI 2 inside zeolites.…”