1,2-Difluorobenzene

1,2-Difluorobenzene, also known as DFB, is an aromatic compound with formula C6H4F2. This colorless liquid is a solvent used in the electrochemical studies of transition metal complexes. Compared to most conventional halogenated aliphatic and aromatic solvents, it possesses an exceptionally high dielectric constant (ε0 = 13.8 at 300 K). Thus, it can be a suitable solvent for cationic, and/or highly electrophilic organometallic complexes.[2]

1,2-Difluorobenzene[1]
Difluorobenzene molecule
Names
Preferred IUPAC name
1,2-Difluorobenzene
Other names
o-Difluorobenzene
ortho-Difluorobenzene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.006.074
UNII
  • InChI=1S/C6H4F2/c7-5-3-1-2-4-6(5)8/h1-4H checkY
    Key: GOYDNIKZWGIXJT-UHFFFAOYSA-N checkY
  • InChI=1/C6H4F2/c7-5-3-1-2-4-6(5)8/h1-4H
    Key: GOYDNIKZWGIXJT-UHFFFAOYAN
  • Fc1ccccc1F
Properties
C6H4F2
Molar mass 114.093 g/mol
Appearance colorless liquid
Density 1.1599 g/cm3
Melting point −34 °C (−29 °F; 239 K)
Boiling point 92 °C (198 °F; 365 K)
(insoluble) 1.14 g/L
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references

Synthesis

1,2-Difluorobenzene is prepared by a simple substitution reaction of fluorine with fluorobenzene.

C6H5F + F2 → C6H4F2 + HF

The 1,4-isomer and small amounts of the 1,3-isomer are also produced in the reaction as the fluorine group on the aromatic ring of fluorobenzene is ortho- and para- directing.

Laboratory applications

1,2-Difluorobenzene has been used as solvent for the electrochemical analysis of transition metal complexes. It is relatively chemically inert, weakly coordinating and has a relatively high dielectric constant. It is a weakly coordinating for metal complexes, in contrast to acetonitrile, DMSO, and DMF.[3]

It has anaesthetic properties.[4]

1,2-Difluorobenzene can be acylated to 3',4'-difluoropropiophenone.[5]

Hazards

DFB is flammable.

References
  1. David R. Lide, ed., CRC Handbook of Chemistry and Physics, 89th Edition (Internet Version 2009), CRC Press/Taylor and Francis, Boca Raton, FL.
  2. Pike, Sebastian D.; Crimmin, Mark R.; Chaplin, Adrian B. (2017). "Organometallic chemistry using partially fluorinated benzenes" (PDF). Chemical Communications. 53 (26): 3615–3633. doi:10.1039/C6CC09575E. PMID 28304406.
  3. O'toole, Terrence R.; Younathan, Janet N.; Sullivan, B. Patrick; Meyer, Thomas J. (1989). "1,2-Difluorobenzene: a relatively inert and noncoordinating solvent for electrochemical studies on transition-metal complexes". Inorganic Chemistry. 28 (20): 3923. doi:10.1021/ic00319a032.
  4. "1,2-Difluorobenzene". PubChem. Retrieved 11 February 2021.
  5. GB 1140754, Danilewicz, John Christopher & Szelke, Michael, "3,4-difluorophenyl compounds", published 1969-01-22, assigned to Pfizer Ltd.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.