Chemistry:Disulfur dinitride
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| Names | |
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| Preferred IUPAC name
Disulfur dinitride | |
| Systematic IUPAC name
1λ4,3,2,4-Dithiadiazete | |
| Other names
Cyclic sulfur(II,IV) nitride
1,3-dithia-2,4-diazacyclobutan-2,4-diyl | |
| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
PubChem CID
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| Properties | |
| S 2N 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 | |
Disulfur dinitride is the chemical compound with the formula S
2N
2.
Preparation and reactions
Passing gaseous S
4N
4 over silver metal wool at 250–300 °C at low pressure (1 mmHg) yields cyclic S
2N
2. The silver reacts with the sulfur produced by the thermal decomposition of the S
4N
4 to form Ag
2S, and the resulting Ag
2S catalyzes the conversion of the remaining S
4N
4 into the four-membered ring S
2N
2,[1]
- S
4N
4 + 8 Ag → 4 Ag
2S + 2 N
2 - S
4N
4 → 2 S
2N
2
An alternative uses the less explosive S
4N
3Cl.[2]
S
2N
2 decomposes explosively above 30 °C, and is shock sensitive.[1] It readily sublimes, and is soluble in diethyl ether. Traces of water[2] or other nucleophiles cause it to polymerize into S
4N
4.[3] In the solid state it spontaneously polymerizes forming (SN)
n,[1] catalyzed by radical impurities.[3] It forms adducts with Lewis acids via a nitrogen atom, e.g. S
2N
2 · BCl
3, S
2N
2 · 2AlCl
3, S
2N
2 · SbCl
5, S
2N
2 · 2SbCl
5.[2][4]
Structure and bonding
The S
2N
2 molecule is a four-membered ring, with alternating S and N atoms. The molecule is almost square and planar. The S–N bond lengths are 165.1 pm and 165.7 pm and the bond angles are very close to 90°.[1]
The S
2N
2 molecule is isoelectronic with the cyclic S2+
4 dication,[2] but the oft-quoted description of S
2N
2 bearing 6 π electrons is inaccurate. According to spin-coupled valence bond analysis, the molecule is instead better interpreted as two conjoined sulfur diimides: each sulfur atom bears a single +1 formal charge and one lone pair and each nitrogen atom a single -1 formal charge and two lone pairs. The remaining two electrons, each located on sulfur, are coupled across the ring as a singlet diradical. Loosely, the HOMO and LUMO of S
2N
2 are each nonbonding orbitals corresponding to these two electrons.[5]
See also
References
- ↑ 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.
- ↑ 2.0 2.1 2.2 2.3 Wiberg, E.; Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. ISBN 0-12-352651-5.
- ↑ 3.0 3.1 Oakley, Richard T.. "Cyclic and heterocyclic thiazines". in Lippard, Stephen L.. Progress in Inorganic Chemistry. 36. NY, NY: Interscience. ISBN 0-471-61144-1.
- ↑ 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.
- ↑ 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. Bibcode: 1996JAChS.118.6472G.
| 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 | |||
 |  |
