REACTIONS OF ARSINIC AND ARSONIC ACIDS WITH H₂S AND H₂Se: CRYSTAL STRUCTURE OF 1,4-DIPHENYL-1,4-DIARSA-2,3,5-TRISELENACYCLOPENTANE

An unusual occurrence of arsenic-bearing pyrite in the Upper Freeport coal bed, west-central Pennsylvania

“…ECU/t (dal) Figure 10. Effect of environmental and socioeconomic credits at 3 ECUs/GJ on costs of crude and refined products (1 ECU Introduction Arsenic is known to concentrate in coal1,2 relative to Clarke values.1 23 Although As can be associated with organic matter and clay minerals in coal,4 *it is more typically (1) Chapman, A. C. The Analyst 1901, 26, 139-159.…”

“…For example, dimethylarsinic acid can react directly with S compounds by forming -S-AsMe2 derivatives. 23 Tolerance of plants to As is related to dosage and modifying parameters including plant species, soil types, and climate.4 Although the tolerance of As by Pennsylvanian age plants such as lycopods, tree ferns, and seed ferns cannot be known, modern ferns can contain up to 3.5 ppm As on a dry-weight basis. 19 Tropical temperatures are known to increase As uptake in modern plants4 and may have done so in Pennsylvanian age plants.…”

A Survey of Supramolecular Aggregation Based on Main Group Element⋯Selenium Secondary Bonding Interactions—A Survey of the Crystallographic Literature

“…Figure 7d. A third topology for the chain is seen in the crystal of 25 [50] where the molecule is disposed about a 2-fold axis of symmetry. There are on average two As• • • Se interactions between the molecules and being propagated by glide symmetry; the chain has a zigzag topology, Figure 7e.…”

“…whereby only one of the three potential arsenic(III) atoms and one of the two selenium atoms are engaged in As … Se interactions to form a chain with a helical topology being propagated by 21-screw symmetry, Figure 7d. A third topology for the chain is seen in the crystal of 25 [50] where the molecule is disposed about a 2-fold axis of symmetry. There are on average two As … Se interactions between the molecules and being propagated by glide symmetry; the chain has a zigzag topology, Figure 7e.…”

“…In cluster compound 49 [69], the osmium atoms of the Os3(CO)9 core are μ3-capped on either side by tellurium and selenium atoms, which associate in the crystal to form a linear, supramolecular chain with an average of one Te … Se interaction per repeat unit, Figure 13f. In isostructural 50 and 51 [70], constructed about M3O cores, M = Zr (50) and Hf (51), and featuring an unusual TeSe3 capping residue, molecules associate into helical chains (21 screw symmetry) via Te … Se interactions. Similar helical chains are observed in 52, Figure 13g, and 53 [71], which differ in the nature of the atom connecting the aromatic ring to the selenium atom bonded to the tellurium atom, the latter associate to form the chain.…”