Langbahn Team – Weltmeisterschaft

Selenocyanate

Selenocyanate
Identifiers
3D model (JSmol)
1848016
ChEBI
ChEMBL
ChemSpider
81789
  • InChI=1S/CHNSe/c2-1-3/h3H/p-1
    Key: CRDYSYOERSZTHZ-UHFFFAOYSA-M
  • C(#N)[Se-]
Properties
CNSe−
Molar mass 104.990 g·mol−1
Related compounds
Related compounds
 thiocyanate; cyanate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

A selenocyanate is an ion or chemical compound that contains the -SeCN group, which could be in the form of an anion, SeCN−. Organic selenocyanates also exist.

Some complex ions with transition metals such as silver and mercury (mercuriselenocyanates) are known. Mercuriselenocyanate salts also include K, Fe, Co, Ni, Cu, Zn, and Cd.[1] Complex ions include Fe(NCSe)63−, Fe(NCSe)64−, Fe(NCSe)42−, Co(NCSe)64−, Co(NCSe)42−, Ni(NCSe)64−, Zn(NCSe)64−, Rh(NCSe)64−, Pd(NCSe)42−, Ag(SeCN)2−, Cd(NCSe)42−, Cd(NCSe)64−, Dy(NCSe)63−, Ho(NCSe)63−, Er(NCSe)63−, Pt(NCSe)62−, Au(NCSe)4−, and Hg(NCSe)42−.[2]

For hard metals, the negative charge is on the nitrogen atom which coordinates with the metal atom. Examples include Ti(NCSe)62−, V(NCSe)63−, VO(NCSe)42−, Cr(NCSe)63−, Mn(NCSe)42−, Mn(NCSe)42−, Y(NCSe)63−, Zr(NCSe)62−, Mo(NCSe)63−, Pr(NCSe)63−, Nd(NCSe)63−, Sm(NCSe)63−, Hf(NCSe)62−, Re2(NCSe)82−, Pa(NCSe)84− and U(NCSe)84−.[3]

Production

Selenocyanate can be produced in the reaction of selenium, selenide, selenite or selenate with cyanide ions.[4]

Se2− + CN− + 0.5 O2 → SeCN− + 2OH−
SeO32− + 3CN− → 2OCN− + SeCN− + 2OH−
SeO42− + 4CN− → 3OCN− + SeCN− + 2OH−

Reactions

Selenocyanate is oxidised to selenium and cyanate by bis (trifluoroacetoxy) iodobenzene.[5]

Application

Selenocyanate is component of pollution from oil refineries and mine drainage water. Remediation methods have been investigated to extract selenocyanate from water. Methods considered include precipitation by metal salts, or extraction by plants. Indian mustard converts some selenocyanate to selenocystine and selenomethionine, and volatiles dimethylselenide and methylselenocyanate.[6]

List

formula crystal form space group Å volume density comment reference
[NH4][SeCN] monoclinic P21/c a=4.3443 b=7.3615 c=12.9858 β=99.152° Z=4 416.99 pink due to contamination from red selenium [7]
KSeCN monoclinic P21/c a=4.59 b=7.64 c=11.89 β=101.13° [8]
Ag[SeCN] monoclinic C2/c a=8.8300 b=8.2471 c=8.4303 β=93.027° Z=8[9] 613.05 solubility at 18°: 2.0×10−8 Mol/litre [7]
[NH4][Ag(SeCN)2] orthorhombic Pbca a=7.15549 b=20.0671 c=10.4776 Z=8 1504.49 [7]
[NH4]3[Ag(SeCN)4] tetragonal I41/acd a=14.0013 c=31.4678 Z=16 6168.8 [7]
[NH4]0.7K0.3[SeCN] [7]
K2Hg(CNSe)4 [6]
[Cu(IPr)(NCSe)]2 IPr = 1,3- bis(2,6-diisopropylphenyl)imidazol-2-ylidene triclinic P1 a=9.389 b=10.9745 c=14.0542 101.181 90.311 105.620 Z=1 1365.7 @100K [10]
ZnHg(CNSe)4 [6]
CdHg(CNSe)4 [6]

References

  1. ^ Benedetti-Pichler, A. A.; Spikes, W. F. (December 1934). "The use of potassium mercuri-selenocyanate as a reagent in qualitative microanalysis". Mikrochemie. 15 (1): 271–287. doi:10.1007/BF02789376. ISSN 0369-0261.
  2. ^ Advances in Inorganic Chemistry and Radiochemistry. Academic Press. 2 May 1975. p. 355. ISBN 978-0-08-057866-8.
  3. ^ Advances in Inorganic Chemistry and Radiochemistry. Academic Press. 2 May 1975. p. 354. ISBN 978-0-08-057866-8.
  4. ^ Hullebusch, Eric D. van (2 September 2017). Bioremediation of Selenium Contaminated Wastewater. Springer. pp. 110–111. ISBN 978-3-319-57831-6.
  5. ^ Papadoyannis, I. N.; Stratis, J. A.; Anthemidis, A. N. (January 1984). "Simultaneous Determination of Selenocyanate and Thiocyanate Ions in the Presence of Cyanide by Oxidation with bis (Trifluoroacetoxy) iodobenzene". Analytical Letters. 17 (13): 1511–1517. doi:10.1080/00032718408065325. ISSN 0003-2719.
  6. ^ a b c d de Souza, Mark P.; Pickering, Ingrid J.; Walla, Michael; Terry, Norman (1 February 2002). "Selenium Assimilation and Volatilization from Selenocyanate-Treated Indian Mustard and Muskgrass". Plant Physiology. 128 (2): 625–633. doi:10.1104/pp.010686. PMC 148924. PMID 11842165.
  7. ^ a b c d e Shlyaykher, Alena; Tambornino, Frank (15 July 2023). "Synthesis and Stability of Ammonium Selenocyanate [NH 4 ][SeCN] and Its Reactivity toward Ag[SeCN]". Inorganic Chemistry. 62 (30): 11943–11953. doi:10.1021/acs.inorgchem.3c01345. PMID 37453070. S2CID 259924312.
  8. ^ Swank, Duane D.; Willett, Roger D. (April 1965). "The Crystal Structure of Potassium Selenocyanate". Inorganic Chemistry. 4 (4): 499–501. doi:10.1021/ic50026a013. ISSN 0020-1669.
  9. ^ Salomon, Mark; Salomon, M.; Ohtaki, H. (3 September 2013). Silver Azide, Cyanide, Cyanamides, Cyanate, Selenocyanate and Thiocyanate: Solubilities of Solids. Elsevier. p. 92. ISBN 978-1-4831-5492-3.
  10. ^ Dodds, Christopher A.; Kennedy, Alan R.; Thompson, Ross (2019-08-25). "Taming Copper(I) Cyanate and Selenocyanate with N-Heterocyclic Carbenes" (PDF). European Journal of Inorganic Chemistry. 2019 (31): 3581–3587. doi:10.1002/ejic.201900515. ISSN 1434-1948. S2CID 202034228.
Quelle: https://en.wikipedia.org/wiki/Selenocyanate