Sulfur dicyanide

Sulfur dicyanide
Identifiers
CAS Number
  • 627-52-1
3D model (JSmol)
  • Interactive image
ChemSpider
  • 120218
PubChem CID
  • 136447
CompTox Dashboard (EPA)
  • DTXSID70211767 Edit this at Wikidata
InChI
  • InChI=1S/C2N2S/c3-1-5-2-4
    Key: RFMQOHXWHFHOJF-UHFFFAOYSA-N
  • C(#N)SC#N
Properties
Chemical formula
 C2N2S
Molar mass 84.10 g·mol−1
Appearance white solid
Density 1.48 g/cm3
Melting point 62.3 °C (144.1 °F; 335.4 K)[1]
Sublimation
conditions
 30–40 °C, 1 atm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Chemical compound

Sulfur dicyanide is an inorganic compound with the formula S(CN)2. A white, slightly unstable solid, the compound is mainly of theoretical and fundamental interest given its simplicity.[2]: 8  It is the first member of the dicyanosulfanes Sx(CN)2, which includes thiocyanogen ((SCN)2) and higher polysulfanes up to S4(CN)2.[3] According to X-ray crystallography, the molecule is planar, the SCN units are linear, with an S-C-S angle of 95.6°.[4]

Sulfur dicyanide begins to sublime at 30-40 °C and melts at 60 °C.[5] Under an inert atmosphere, it slowly decomposes to a yellow polymer at room temperature with a rate increasing in temperature.[2]: 8, 14  The compound is unstable in acid, disproportionating to thiocyanate, cyanate, hydrogen sulfate,and cyanide,[1] and neutral moisture induces decomposition to thiocyanic and cyanic acids. Stable solutions are possible in many organic solvents.[2]: 14 

Sulfur dicyanide was first synthesized by Lassaigne in 1828 from silver cyanide and sulfur dichloride.[2]: 8  Subsequent developments include Linneman's discovery that the same product arose from silver thiocyanate and cyanogen iodide,[5] and Söderbäck's extensive analysis of reactions between metal cyanides and sulfur halides.[6] Linneman also discovered that sulfur dicyanide reacts with ammonia à la Pinner to give an amidine without displacing the S–C linkage,[5] although dimethylamine induces decomposition to dimethylcyanamide and dimethylammonium thiocyanate.[2]: 14 

Sulfur dicyanide generally reacts with noble metals to give heteroleptic cyano-thiocyano complices, although in rare cases it can ligate without decomposition, e.g.:[2]: x 

Ir(CO)(PPh3)2Cl + NCSCN → Ir(CO)(CN)(SCN)(PPh3)2Cl
Ir(N2)(PPh3)2Cl + S(CN)2 → Ir(S(CN)2)(PPh3)2Cl

References

  1. ^ a b Wilson, I. R.; Harris, G. M. (January 1, 1961). "The oxidation of thiocyanate ion by hydrogen peroxide II: The acid-catalyzed reaction". Journal of the American Chemical Society. 83 (2). doi:10.1021/ja01463a007.
  2. ^ a b c d e f Hamilton, Diane Singleton (26 November 1974). Reactions of Sulfur-Dicyanide and Sulfur-Dichlorides with Transition Metal Complexes (PhD). Louisiana State University and Agricultural & Mechanical College.
  3. ^ Steudel, Ralf; Bergemann, Klaus; Kustos, Monika (1994). "Crystal and Molecular Structure of Dicyanotetrasulfane S4(CN)2". Zeitschrift für anorganische und allgemeine Chemie. 620: 117–120. doi:10.1002/zaac.19946200119.
  4. ^ Emerson, K. (1966). "The Crystal and Molecular Structure of Sulfur Dicyanide". Acta Crystallographica. 21 (6): 970–974. Bibcode:1966AcCry..21..970E. doi:10.1107/S0365110X66004262.
  5. ^ a b c Linneman, F. (1861). "Untersuchung über das Cyansulfid" [Research on cyanogen sulfide]. Liebigs Annalen der Chemie (in German). 120 (1): 36–47. doi:10.1002/jlac.18611200103 – via HathiTrust.
  6. ^ Söderbäck, Erik (1919). "Studien über das freie Rhodan". Justus Liebig's Annalen der Chemie. 419 (3): 217–322. doi:10.1002/jlac.19194190302.
  • v
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Salts and covalent derivatives of the cyanide ion
HCN He
LiCN Be(CN)2 B(CN)3 C(CN)4
C2(CN)2 		NH4CN
ONCN
O2NCN
N3CN 		OCN−
-NCO
O(CN)2 		FCN Ne
NaCN Mg(CN)2 Al(CN)3 Si(CN)4
(CH3)3SiCN 		P(CN)3 SCN−
-NCS
(SCN)2
S(CN)2 		ClCN Ar
KCN Ca(CN)2 Sc(CN)3 Ti V Cr(CN)63− Mn Fe(CN)2
Fe(CN)64−
Fe(CN)63− 		Co(CN)2
Co(CN)3−
5 		Ni(CN)2
Ni(CN)42−
Ni(CN)44− 		CuCN Zn(CN)2 Ga(CN)3 Ge(CN)2
Ge(CN)4 		As(CN)3
(CH3)2AsCN
(C6H5)2AsCN 		SeCN−
(SeCN)2
Se(CN)2 		BrCN Kr
RbCN Sr(CN)2 Y(CN)3 Zr Nb Mo(CN)84− Tc Ru Rh Pd(CN)2 AgCN Cd(CN)2 In(CN)3 Sn(CN)2 Sb(CN)3 Te(CN)2
Te(CN)4 		ICN Xe
CsCN Ba(CN)2 * Lu(CN)3 Hf Ta W(CN)84− Re Os Ir Pt(CN)42-
Pt(CN)64-
 AuCN
Au(CN)2- 		Hg2(CN)2
Hg(CN)2 		TlCN Pb(CN)2 Bi(CN)3 Po At Rn
Fr Ra ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
 
* La(CN)3 Ce(CN)3
Ce(CN)4 		Pr(CN)3 Nd Pm Sm(CN)3 Eu(CN)3 Gd(CN)3 Tb Dy(CN)3 Ho(CN)3 Er Tm Yb(CN)3
** Ac(CN)3 Th(CN)4 Pa UO2(CN)2 Np Pu Am Cm Bk Cf Es Fm Md No