Chemistry:Disulfur dinitride

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Disulfur dinitride
Space-filling model of disulfur dinitride
Names
Preferred IUPAC name
Disulfur dinitride
Systematic IUPAC name
4,3,2,4-Dithiadiazete
Other names
Cyclic sulfur(II,IV) nitride
1,3-dithia-2,4-diazacyclobutan-2,4-diyl
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
Properties
S
2
N
2
Molar mass 92.1444 g/mol
Appearance colourless crystals
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Tracking categories (test):

Disulfur dinitride is the chemical compound with the formula S
2
N
2
.

Preparation and reactions

Passing gaseous S
4
N
4
over silver metal wool at 250–300 °C at low pressure (1mm Hg) yields cyclic S
2
N
2
. The silver reacts with the sulfur produced by the thermal decomposition of the S
4
N
4
to form Ag
2
S
, and the resulting Ag
2
S
catalyzes the conversion of the remaining S
4
N
4
into the four-membered ring S
2
N
2
,[1]

S
4
N
4
+ 8 Ag → 4 Ag
2
S + 2 N
2
S
4
N
4
→ 2 S
2
N
2

An alternative uses the less explosive S
4
N
3
Cl
.[2][clarification needed]

S
2
N
2
decomposes explosively above 30°C, and is shock sensitive.[1] It readily sublimes, and is soluble in diethyl ether. Traces of water cause it to polymerize into S
4
N
4
.[2] In the solid state it spontaneously polymerizes forming (SN) {n}.[1] It forms adducts with Lewis acids via a nitrogen atom, e.g. S
2
N
2
 · BCl
3
, S
2
N
2
 · 2AlCl
3
, S
2
N
2
 · SbCl
5
, S
2
N
2
 · 2SbCl
5
.[2][3]

Structure and bonding

The S
2
N
2
molecule is a four-membered ring, with alternating S and N atoms. One S atom has valence 4 and the other S atom has valence 2. Both nitrogen atoms has valence 3. The molecule is almost square and planar. The S–N bond lengths are 165.1pm and 165.7pm and the bond angles are very close to 90°.[1] The S
2
N
2
molecule is isoelectronic with the cyclic S2+
4
dication and has 6π electrons.[2] The bonding has been investigated using a spin-coupled valence bond method [4] and is described as having four framework sigma bonds, with the N atoms bearing a high negative charge and the S atoms a corresponding positive charge. Two π electrons from the sulfur atoms are coupled across the ring making the molecule overall a singlet diradical.

See also

References

  1. 1.0 1.1 1.2 1.3 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 
  2. 2.0 2.1 2.2 2.3 Wiberg, E.; Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. ISBN 0-12-352651-5. 
  3. Patton R. L.; Raymond, K. N. (1969). "The Crystal and Molecular Structure of S2N2(SbCl5)2". Inorganic Chemistry 8 (11): 2426–2431. doi:10.1021/ic50081a035. 
  4. Gerratt, J.; McNicholas, S. J.; Karadakov, P. B.; Sironi, M.; Raimondi, M.; Cooper, D. L. (1996). "The Extraordinary Electronic Structure of N2S2". Journal of the American Chemical Society 118 (27): 6472–6476. doi:10.1021/ja953994f. 
Salts and covalent derivatives of the nitride ion
NH3 He(N2)11
Li3N Be3N2 BN β-C3N4
g-C3N4
N2 NxOy NF3 Ne
Na3N Mg3N2 AlN Si3N4 PN
P3N5
SxNy
SN
S4N4
NCl3 Ar
K3N Ca3N2 ScN TiN VN CrN
Cr2N
MnxNy FexNy CoN Ni3N CuN Zn3N2 GaN Ge3N4 As Se NBr3 Kr
Rb3N Sr3N2 YN ZrN NbN β-Mo2N Tc Ru Rh PdN Ag3N CdN InN Sn Sb Te NI3 Xe
Cs3N Ba3N2   Hf3N4 TaN WN Re Os Ir Pt Au Hg3N2 TlN Pb BiN Po At Rn
Fr3N Ra3N   Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
La CeN Pr Nd Pm Sm Eu GdN Tb Dy Ho Er Tm Yb Lu
Ac Th Pa UN Np Pu Am Cm Bk Cf Es Fm Md No Lr