Thiazyl fluoride

Thiazyl fluoride

Identifiers
CAS Number	18820-63-8  N
3D model (JSmol)	Interactive image
ChemSpider	123854  Y
PubChem CID	140430
CompTox Dashboard (EPA)	DTXSID00172170
InChI InChI=1S/FNS/c1-3-2 Y Key: IMFUYZDKLVTPSW-UHFFFAOYSA-N Y InChI=1/FNS/c1-3-2 Key: IMFUYZDKLVTPSW-UHFFFAOYAG
SMILES FS#N
Properties
Chemical formula	NSF
Molar mass	65.07 g·mol−1
Appearance	colourless gas
Melting point	−89 °C (−128 °F; 184 K)
Boiling point	0.4 °C (32.7 °F; 273.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Thiazyl fluoride is a compound with the chemical formula N S F . It is a colourless, pungent gas at room temperature and condenses to a pale yellow liquid at 0.4 °C. ^[1] Along with thiazyl trifluoride, NSF₃, it is a precursor to sulfur-nitrogen-fluorine compounds.

Synthesis

Thiazyl fluoride can be synthesized by the reaction of imino(triphenyl)phosphines with sulfur tetrafluoride by cleavage of the bond to form sulfur difluoride imides and triphenyldifluorophosphorane. ^[2] These products readily decompose yielding thiazyl fluoride. Another method is fluorination of tetrasulfur tetranitride with silver(II) fluoride or mercuric fluoride followed by vacuum distillation. ^{[3] [4]} This method, however, yields numerous side-products.

For synthesis on a preparative scale, the decomposition of compounds already containing the moiety is commonly used: ^[5]

Reactivity

Reactions with electrophiles and Lewis acids

Lewis acids remove fluoride to afford thiazyl salts: ^[6]

NSF + BF₃ → [N≡S]⁺[BF₄]⁻

Thiazyl fluoride functions as a ligand in [Re(CO)₅NSF]⁺. ^[1] and [M(NSF)₆]²⁺ (M = Co, Ni). In all of its complexes, NSF is bound to the metal center through nitrogen. ^[7]

Reactions with nucleophiles

Thiazyl fluoride reacts violently with water: ^[8]

NSF + 2 H₂O → SO₂ + HF + NH₃

Nucleophilic attack on thiazyl fluoride occurs at sulfur atom:. ^[9]

NS−F + Nu ⁻ → NS−Nu + F⁻

Fluoride gives an adduct:

NS−F + F⁻ → NSF−2

The halogen derivatives X−N=SF₂ (X = F, Cl, Br, I) can be synthesized from reacting Hg(NSF)₂ with X₂; whereby, ClNSF₂ is the most stable compound observed in this series. ^[10]

Oligomerization and cycloaddition

At room temperature, thiazyl fluoride trimerizes:

In the product 1,3,5-trifluoro-1λ⁴,3λ⁴,5λ⁴-2,4,6-trithiatriazine, each sulfur atom remains tetravalent.

Thiazyl fluoride also participates in cycloaddition in the presence of dienes.

Structure and bonding

The N−S bond length is 1.448 Å, which is short, indicating multiple bonding, and can be represented by the following resonance structures:

The NSF molecule has 18 total valence electrons and is isoelectronic to sulfur dioxide. Thiazyl fluoride adopts C_s-symmetry and has been shown by isotopic substitution to be bent in the ground state. ^{[11] [12]} A combination of rotational analysis with Franck-Condon calculations has been applied to study the electronic excitation from the A''${\displaystyle -}$A' states, which results in the elongation of the nitrogen-sulfur bond by 0.11 Å and a decrease in the ${\displaystyle \measuredangle }$NSF by 15.3${\displaystyle ^{\circ }}$.

References

1. Oskar Glemser and Rüdiger Mews (1980). "Chemistry of Thiazyl Fluoride (NSF) and Thiazyl Trifluoride (NSF₃): A Quarter Century of Sulfur-Nitrogen-Fluorine Chemistry". Angew. Chem. Int. Ed. Engl. 19 (11): 883–899. doi:10.1002/anie.198008831.
2. Appel, Rolf; Laßmann, Eberhard (July 1971). "Über eine neue Synthese des Thiazylfluorids, NSF" . Chemische Berichte. 104 (7): 2246–2249. doi:10.1002/cber.19711040727. ISSN   0009-2940.
3. Fischer, Gad (1974-05-01). "Vibrational assignments in the electronic spectra of thiazyl fluoride" . Journal of Molecular Spectroscopy. 51 (2): 208–215. Bibcode:1974JMoSp..51..208F. doi:10.1016/0022-2852(74)90050-2. ISSN   0022-2852.
4. Glemser, Oskar; Schröder, Hans; Haeseler, Harke (1955-01-01). "Über Schwefel-Stickstoff-Fluorverbindungen" . Naturwissenschaften (in German). 42 (2): 44. Bibcode:1955NW.....42...44G. doi:10.1007/BF00621536. ISSN   1432-1904. S2CID   32868758.
5. Roesky, H. W. (1971). "The Sulfur–Nitrogen Bond". In Senning, Alexander (ed.). Sulfur in Organic and Inorganic Chemistry. Vol. 1. New York: Marcel Dekker. p. 22. ISBN   0-8247-1615-9. LCCN   70-154612.
6. Mews, Rüdiger (November 1976). "Das Thionitrosylkation NS+ als Synthesereagens" . Angewandte Chemie (in German). 88 (22): 757–758. Bibcode:1976AngCh..88..757M. doi:10.1002/ange.19760882205.
7. Oskar Glemser and Rüdiger Mews (1980). "Chemistry of Thiazyl Fluoride (NSF) and Thiazyl Trifluoride (NSF₃): A Quarter Century of Sulfur-Nitrogen-Fluorine Chemistry". Angew. Chem. Int. Ed. Engl. 19 (11): 883–899. doi:10.1002/anie.198008831.
8. Mews, Rudiger; Keller, Klaus; Glemser, Oskar; Seppelt, K.; Thrasher, J. (2007-01-05), Shreeve, Jean'ne M. (ed.), "Acyclic Sulfur Nitrogen Fluorine Compounds" , Inorganic Syntheses, Hoboken, NJ, USA: John Wiley & Sons, Inc., pp. 12–17, doi:10.1002/9780470132555.ch6, ISBN   978-0-470-13255-5 , retrieved 2022-12-15
9. Cohen, B.; Hooper, T. R.; Hugill, D.; Peacock, R. D. (August 1965). "Preparation of Thiazyl Fluorides" . Nature. 207 (4998): 748–749. Bibcode:1965Natur.207..748C. doi:10.1038/207748b0. ISSN   1476-4687. S2CID   4163539.
10. Glemser, Oskar; Mews, Rüdiger; Roesky, Herbert W. (May 1969). "Darstellung und Eigenschaften von Quecksilber-bis-schwefeldifluoridimid, N -Chlor-schwefeldifluoridimid und N -Brom-schwefeldifluoridimid" . Chemische Berichte. 102 (5): 1523–1528. doi:10.1002/cber.19691020513. ISSN   0009-2940.
11. So, Suk Ping; Richards, W. Graham (1978-01-01). "Geometries and stabilities of NSF and SNF" . Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics. 74: 1743–1745. doi:10.1039/F29787401743. ISSN   0300-9238.
12. Dixon, R. N.; Duxbury, G.; Fleming, G. R.; Hugo, J. M. V. (1972-05-01). "The photoelectron spectrum of thiazyl fluoride" . Chemical Physics Letters. 14 (1): 60–63. Bibcode:1972CPL....14...60D. doi:10.1016/0009-2614(72)87141-0. ISSN   0009-2614.