| Abstract
| - The product of the reaction of HgCl2 vapor with fully dehydrated fully NH4+-exchanged zeolite X at 115 °C,ca. Hg44Cl64(NH4)68−Si100Al92O384 per unit cell, was studied by single-crystal X-ray diffraction techniques at23 °C (R1 = 0.121) in the cubic space group Fd3̄ (a0 = 25.094(8) Å). Hg2+ ions are found at sevennonequivalent sites, a surprisingly large number. Hg2+ ions at sites I and II each coordinate only to frameworkoxygens; this is the first observation of Hg2+ ions at conventional ionic sites in a zeolite, and of very nearlyregular octahedral Hg(II), and of three-coordinate trigonal Hg(II). Hg2+ ions at two general site III‘ positionsform (HgCl2)3(NH4+)2 and (HgCl2)3(NH4+) clusters, respectively, in 12-rings with each Hg2+ ion bonding toone framework oxygen. The Hg2+ ions at another two general site III‘ positions form (HgCl2)6(NH4+)2 clusters,also in 12-rings with each Hg2+ ion bonding to two framework oxygens. These two clusters could bridgethrough Cl- ions to form a supercluster that contains as alternative subunits Hg12Cl12 rings each of whichwraps around a double six-ring. Site II is full with two Hg2+ and 30 NH4+ ions. In each sodalite cage, anNH4+ ion at site I‘ bonds to three framework oxygens. Two Hg2+ ions per unit cell are seen near supercagecenters; each coordinates to three Cl- ions that bridge to other Hg2+ ions. The desired reaction of NH4-Xwith HgCl2 vapor did not go to completion. Substantial amounts of HgCl2 were sorbed and cationic superclustersof Hg(II) and Cl- have formed. This is the first observation of cationic halomercuric species.
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