Thiazyl fluoride

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. 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. This method, however, yields numerous side-products.

For synthesis on a preparative scale, the decomposition of compounds already containing the moiety is commonly used: :[[File:Thiazyl fluoride decomposition syntheses.webp|class=skin-invert-image|frameless|left|upright=1.5]]

Reactivity

Reactions with electrophiles and Lewis acids

Lewis acids remove fluoride to afford thiazyl salts: :

Thiazyl fluoride functions as a ligand in . and (M = Co, Ni). In all of its complexes, NSF is bound to the metal center through nitrogen.

Reactions with nucleophiles

Thiazyl fluoride reacts violently with water: :

Nucleophilic attack on thiazyl fluoride occurs at sulfur atom:. : Fluoride gives an adduct: :

The halogen derivatives (X = F, Cl, Br, I) can be synthesized from reacting with ; whereby, is the most stable compound observed in this series.

Oligomerization and cycloaddition

At room temperature, thiazyl fluoride trimerizes: :[[File:NSF-trimerization.webp|class=skin-invert-image|frameless|257x257px]]

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:

:[[File:NSF Resonance-Lewis Structure2.webp|class=skin-invert-image|frameless|282x282px]]

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

References

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". [[Angewandte Chemie International Edition in English.
2. (July 1971). "Über eine neue Synthese des Thiazylfluorids, NSF". Chemische Berichte.
3. Fischer, Gad. (1974-05-01). "Vibrational assignments in the electronic spectra of thiazyl fluoride". Journal of Molecular Spectroscopy.
4. (1955-01-01). "Über Schwefel-Stickstoff-Fluorverbindungen". Naturwissenschaften.
5. Roesky, H. W.. (1971). "Sulfur in Organic and Inorganic Chemistry". Marcel Dekker.
6. Mews, Rüdiger. (November 1976). "Das Thionitrosylkation NS+ als Synthesereagens". Angewandte Chemie.
7. Oskar Glemser and Rüdiger Mews. (1980). "Chemistry of Thiazyl Fluoride (NSF) and Thiazyl Trifluoride (NSF₃): A Quarter Century of Sulfur-Nitrogen-Fluorine Chemistry". [[Angewandte Chemie International Edition in English.
8. (2007-01-05). "Acyclic Sulfur Nitrogen Fluorine Compounds". John Wiley & Sons, Inc..
9. (August 1965). "Preparation of Thiazyl Fluorides". Nature.
10. (May 1969). "Darstellung und Eigenschaften von Quecksilber-bis-schwefeldifluoridimid, N -Chlor-schwefeldifluoridimid und N -Brom-schwefeldifluoridimid". Chemische Berichte.
11. (1978-01-01). "Geometries and stabilities of NSF and SNF". Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics.
12. (1972-05-01). "The photoelectron spectrum of thiazyl fluoride". Chemical Physics Letters.