Roussin's red salt: Difference between revisions

|verifiedrevid = 405276419

|Name = Roussin's red salt

|ImageFile = RRSalt.png

|ImageFile1 = Roussin's-red-salt-anion-3D-balls.png

|IUPACName = potassium tetranitrosyl-di-μみゅー-sulfidodiiron(''Fe''–''Fe'')(2–)

|OtherNames = Ferrate(2-), tetranitrosyldi-mu-thioxodi-, (Fe-Fe), dipotassium

|Section1 = {{Chembox Identifiers

|CASNo = 58204-17-4

|ChemSpiderID = 142967

|PubChem = 162850

|PubChem_Comment = (formula error)

|SMILES = [K+].[K+].O=N[Fe-]12(N=O)S[Fe-]1(S2)(N=O)N=O

|StdInChI=1S/2Fe.4NO.2S/c;;4*1-2;;/q;;4*+1;2*-2

|StdInChIKey = HAJABACXLZMFIH-UHFFFAOYSA-N

|Section2 = {{Chembox Properties

| Formula = Fe₂N₄K₂O₄S₂

| MolarMass = 374.04 g/mol

| Appearance = Dark red crystals

}}

}}

'''Roussin's red salt''' is the [[inorganic compound]] with the formula K₂[Fe₂S₂(NO)₄]. This [[metal nitrosyl]] was first described by Zacharie Roussin in 1858, making it one of the first synthetic [[iron-sulfur cluster|iron-sulfur clusters]].<ref>{{cite journal|last1=Butler|first1=Anthony R.|title=The chemist Z. Roussin (1827-94)|journal=Journal of Chemical Education|date=July 1982|volume=59|issue=7|pages=549|doi=10.1021/ed059p549|bibcode=1982JChEd..59..549B}}</ref><ref>{{cite journal | title = Recherches sur les nitrosulfures doubles de fer (nouvelle classe de sels) | author = Roussin, M. L.

| journal = Ann. Chim. Phys. | volume = 52 | pages = 285–303 | year = 1858 | url = http://gallica.bnf.fr/ark:/12148/bpt6k347939/f284.table }}</ref>

Roussin's red salt anion is an edge-shared bitetrahedron, wherein a pair Fe(NO)₂ units are bridged by a pair of [[sulfide]] ligands. The Fe-[[nitrosyl|NO]] bonds are linear indicating NO is acting as a three electron donor.<ref name="thomas">{{cite journal|last1=Thomas|first1=J. T.|last2=Robertson|first2=J. H.|last3=Cox|first3=E. G.|title=The crystal structure of Roussin's red ethyl ester|journal=Acta Crystallographica|date=1 September 1958|volume=11|issue=9|pages=599–604|doi=10.1107/S0365110X58001602|doi-access=free}}</ref> The [[diamagnetic]] compound obeys the [[18-electron rule]]. The dark red colour of the complex is attributed to a number of [[Charge-transfer complex|charge-transfer]] interactions between the iron core and nitrosyl ligands.<ref>{{cite journal|last1=Jaworska|first1=Maria|last2=Stasicka|first2=Zofia|title=Structure and UV-Vis spectroscopy of the iron-sulfur dinuclear nitrosyl complexes [Fe₂S₂(NO)₄]²⁻ and [Fe₂(SR)₂(NO)₄]|journal=New Journal of Chemistry|date=2005|volume=29|issue=4|pages=604|doi=10.1039/B409519G}}</ref>

The French chemist Z. Roussin<ref>{{cite journal|last1=Butler|first1=Anthony R.|title=The chemist Z. Roussin (1827-94)|journal=Journal of Chemical Education|date=July 1982|volume=59|issue=7|pages=549|doi=10.1021/ed059p549|bibcode=1982JChEd..59..549B}}</ref> first prepared this salt while investigating reactions between [[nitroprusside]] ion ([Fe(CN)₅NO]^2&minus;) and sulfur.<ref>{{cite journal | title = Über komplexe Stickoxydverbindungen und das sogenannte einwertige Eisen | author = Hans Reihlen, Adolf v. Friedolsheim | journal = Justus Liebigs Annalen der Chemie | volume = 457 | pages = 71–82 | year = 1927

| url = http://gallica.bnf.fr/ark:/12148/bpt6k347939/f284.table | doi = 10.1002/jlac.19274570103}}</ref> The salt can be prepared by the reaction of sulfide salts with iron nitrosyl halides:<ref>{{cite journal

| title = Roussin's Red Salt revisited: reactivity of Fe2 (μみゅー-E) 2 (NO) 42-(E= S, Se, Te) and related

| author1 = TB Rauchfuss | author2 = TD Weatherill | journal = Inorganic Chemistry | volume = 21

| issue = 2 | pages = 827–830 | year = 1982 | doi = 10.1021/ic00132a071 }}</ref>

:Fe₂I₂(NO)₄ + 2Li₂S → Li₂Fe₂S₂(NO)₄ + 2LiI

:Li₂Fe₂S₂(NO)₄ + 2 RX → Fe₂(SR)₂(NO)₄ + 2 LiX

It is found in nature as its "esters" with the formula Fe₂(SR)₂(NO)₄, where "R" is any alkyl group.<ref name="thomas" /> In addition Roussin's red salt is discussed in the fields of microbiology and food science due to its mutagenic properties.<ref name="Greenwood">Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. {{ISBN|0-7506-3365-4}}.</ref>

The ester derivative are being investigated as [[nitric oxide]] donors in biology and medicine, due to the relatively low toxicity and good stability of Roussin's red salt.<ref>{{Cite journal|url=https://pubmed.ncbi.nlm.nih.gov/32250631/|pmid = 32250631|year = 2020|last1 = Yoon|first1 = H.|last2 = Park|first2 = S.|last3 = Lim|first3 = M.|title = Photorelease Dynamics of Nitric Oxide from Cysteine-Bound Roussin's Red Ester|journal = The Journal of Physical Chemistry Letters|volume = 11|issue = 9|pages = 3198–3202|doi = 10.1021/acs.jpclett.0c00739|s2cid = 215408785}}</ref>[[Photodissociation]] of the compound induces the release of NO, thereby sensitizing target cells to exposure to radiation.<ref name="Greenwood" />

* [[Roussin's black salt]]

{{Nitric oxide signaling}}

[[Category:Iron complexes]]

[[Category:Nitrosyl complexes]]