Selenium: Inorganic Chemistry

Abstract

Selenium is the first member of the group 16 elements O, S, Se, Te, and Po that shows some metallic character. The increasing metallic character in the series O, S, Se, Te, Po is reflected also in the lower electronegativity, in the less acid character of the oxides, and in the lower stability of the oxidation number +VI for selenium compared to sulfur. There is a large variety of compounds of SeII, SeIV, and SeVI with the electronegative elements N, O, F, Cl, and Br. Thus, there are several types of compounds containing those elements in one molecule. The review will describe the diverse range of cations, oxo‐ and halo‐compounds that selenium forms and their relative structures as haloselenates, selenates, and oxohaloselenates as well as their analogous compounds containing nitrogen and selenium bonded together. Selenides, where selenium as an anion with −2 oxidation number, are presented very briefly, just to underline their properties and wide applications as photoconductors.

Extraction of Se(iv) and Se(vi) from aqueous HCl solution by using a diamide-containing tertiary amine

“…Although [SeOCl 2 ] is not anionic, a higher reactivity can be expected than that of [H 2 SeO 4 ]. 1 A previous study using TBP also showed that TBP did not extract [H 2 SeO 4 ], but instead it extracted [SeOCl 2 ] and [H 2 SeOCl 4 ]. 9 …”

“…Although [SeOCl 2 ] is not anionic, a higher reactivity can be expected than that of [H 2 SeO 4 ]. 1 A previous study using TBP also showed that TBP did not extract [H 2 SeO 4 ], but instead it extracted [SeOCl 2 ] and [H 2 SeOCl 4 ]. 9 Regarding the protonated structure of EHBAA, 21 an H + is chelated by two amide oxygen atoms and an amine nitrogen atom, and a Cl − weakly bonds to an array of polarized C-H d+ units on the opposite side of EHBAA from the protonation site.…”

“…Selenium (Se) has been widely used in various industrial elds. 1,2 Industrial production of Se is mainly achieved by recovery as a byproduct from the anode slimes produced during copper smelting. 3,4 Solvent extraction is one of the important methods for the recovery of Se; however, our understanding of the extraction of Se ions from acidic solutions and the precise speciation of Se ions in relatively concentrated HCl solutions remains largely incomplete.…”

Redox Mo-chloro-species-coupled Se oxidation conversion in low-corrosion ionic liquids for fast-kinetics and durable Zn batteries

“…We take a value of 4 for n throughout the whole theoretical calculations, which is attributed to the fact that Se 4 2+ exhibits a stable square planar ring structure compared to other cluster ions (Se 2 2+ , Se 8 2+ , and Se 12 2+ ). 53 While the reactions for the MoSe 2 electrode are the reversible redox processes of Se species mediated by Mo species (Fig. 5c).…”

“…5b ). 53 While the reactions for the MoSe 2 electrode are the reversible redox processes of Se species mediated by Mo species (Fig. 5c).…”