Selenium tetrachloride

Crystal structure
__ Se 4+      __ Cl -
General
Surname	Selenium tetrachloride
other names	Selenium (IV) chloride
Ratio formula	SeCl 4
Brief description	yellowish solid with a pungent odor
External identifiers / databases
CAS number 10026-03-6 EC number 233-053-5 ECHA InfoCard 100.030.036 PubChem 66205 Wikidata Q2207705
properties
Molar mass	220.77 g mol −1
Physical state	firmly
density	2.6 g cm −3 (25 ° C)
Melting point	305 ° C (under pressure)
Sublimation point	196 ° C
solubility	Decomposes in water practically insoluble in carbon disulfide, carbon tetrachloride and acetyl chloride
Refractive index	1.807 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301 + 331-373-410 P: 261-273-301 + 310-311-501
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Selenium tetrachloride is an inorganic chemical compound of selenium from the group of chlorides .

Extraction and presentation

Selenium tetrachloride can be obtained by reacting selenium with chlorine .

${\displaystyle \mathrm {Se+2\ Cl_{2}\longrightarrow SeCl_{4}} }$

properties

Selenium tetrachloride is a colorless to yellowish moisture-sensitive solid with a pungent odor, which decomposes with water and in moist air to form selenic acid and hydrochloric acid.

${\displaystyle \mathrm {SeCl_{4}+3\ H_{2}O\longrightarrow H_{2}SeO_{3}+4\ HCl} }$

Selenium tetrachloride sublimes when heated. In the closed tube it melts at around 305 ° C to a dark red liquid. It crystallizes cubically in the space group P 4 3 n (space group no. 218) with the lattice parameter a = 16.433 Å . A metastable, monoclinic structure is also known (space group C 2 / c (No. 15) , a = 16.548, b = 9.81, c = 15.029 Å, β = 116.95 °). In concentrated hydrochloric acid, SeCl ₄ forms hexachloroselenates (IV) with alkali chlorides, such as B. the yellow cesium hexachloroselenate (IV) Cs ₂ [SeCl ₆ ].

Individual evidence

1. ↑ ^{a b c d e} data sheet Selenium (IV) chloride at AlfaAesar, accessed on November 24, 2013 ( PDF )(JavaScript required) .
2. ↑ ^{a b c d} data sheet Selenium tetrachloride from Sigma-Aldrich , accessed on May 25, 2017 ( PDF ).
3. ↑ ^{a b c} Georg Brauer , with the assistance of Marianne Baudler a . a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 417 .
4. ^ Henry G. Nowak and John F. Suttle: Selenium (IV) chloride . In: Therald Moeller (Ed.): Inorganic Syntheses . tape 5 . McGraw-Hill, Inc., 1957, pp. 125-127 (English).
5. ^ Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 720 ( limited preview in Google Book Search).
6. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 621.
7. ^ Wilhelm Ostwald: Basic lines of inorganic chemistry . BoD - Books on Demand, 1922, ISBN 3-86195-686-1 , pp. 351 ( limited preview in Google Book Search).
8. ^ R. Kniep, L. Korte, D. Mootz: Crystal structure of the stable modification of SeCl ₄ . In: Zeitschrift für Naturforschung, Part B , 36, 1981, pp. 1660–1662, doi : 10.1515 / znb-1981-1231 .
9. ↑ P. Born, D. Mootz, R. Kniep, M. Hein, B. Krebs: Phase relations in the system Se-SeCl ₄ and the crystal structure of a metastable modification of SeCl ₄ . In: Zeitschrift für Naturforschung, Part B , 36, 1981, pp. 1516-1519, doi : 10.1515 / znb-1981-1206 .
10. ↑ Synthetic Methods of Organometallic and Inorganic Chemistry, Volume 4, 1997: Volume 4: Sulfur, Selenium and Tellurium, WA Herrmann and Christian Erich Zybill, Georg Thieme Verlag, 2014, ISBN 3131794410