Chemistry:4,4'-Bipyridine

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4,4′-Bipyridine
4,4′-bipyridine
4,4′-Bipyridine molecule
4,4'-bipyridine sample.jpg
Names
Preferred IUPAC name
4,4′-Bipyridine
Identifiers
3D model (JSmol)
113176
ChEBI
ChEMBL
ChemSpider
EC Number
  • 209-036-3
3759
UNII
Properties
C10H8N2
Molar mass 156.188 g·mol−1
Melting point 114 °C (237 °F; 387 K)
Boiling point 305 °C (581 °F; 578 K)
Structure
D
Related compounds
Related compounds
2,2′-Bipyridine
Pyridine
4-Pyridylnicotinamide
Terpyridine
Biphenyl
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

4,4′-Bipyridine (abbreviated to 4,4′-bipy or 4,4′-bpy) is an organic compound with the formula (C
5
H
4
N)
2
. It is one of several isomers of bipyridine. It is a colorless solid that is soluble in organic solvents. is mainly used as a precursor to N,N′-dimethyl-4,4′-bipyridinium [(C5H4NCH3)2]2+, known as paraquat.

History

4,4′-Bipyridine was first obtained in 1868 by the Scottish chemist Thomas Anderson via heating pyridine with sodium metal.[1] However, Anderson's empirical formula for 4,4′-bipyridine was incorrect.[2] The correct empirical formula, and the correct molecular structure, for 4,4′-bipyridine was provided in 1882 by the Austrian chemist Hugo Weidel and his student M. Russo.[3]

Uses

4,4'-Bipyridine is an intermediate in the production of paraquat, a widely-used herbicide. In this process, pyridine is oxidized to 4,4'-bipyridine in a coupling reaction, followed by dimethylation to form paraquat.[4]

Paraquat synthesis.svg

Reactions

The reducing agent is N,N'-bis(trimethylsilyl)-4,4'-bipyridinylidene is produced by reduction of 4,4'-bipyridine in the presence of trimethylsilyl chloride (Me = CH3):

NC
5
H
4
C
5
H
4
N + 2 Li + 2 Me
3
SiCl → Me
3
SiNC
5
H
4
C
5
H
4
NSiMe
3
+ 2 LiCl

The silylated derivative, which is red, is used in salt-free reductions.[5]

4,4′-bipyridine forms a variety of coordination polymers.[6]

References

  1. See:
  2. Anderson gave the empirical formula for 4,4′-bipyridine as C10H10N2. See:
    • (Anderson, 1868), p. 209.
    • (Fehling, 1890), p. 974 (γ-Dipyridyl).
  3. Weidel, H.; Russo, M. (1882). "Studien über das Pyridin" (in de). Monatshefte für Chemie 3: 850–885. doi:10.1007/BF01516855. https://babel.hathitrust.org/cgi/pt?id=uiug.30112025861714&view=1up&seq=866.  The empirical formula for 4,4′-bipyridine (γ-Dipyridyl) appears on p. 856 ; the molecular structure of 4,4′-bipyridine (γ-Dipyridyl) appears on p. 867.
  4. "Paraquat and Diquat". IPCS INCHEM. http://www.inchem.org/documents/ehc/ehc/ehc39.htm. 
  5. Tsurugi, Hayato; Mashima, Kazushi (2019). "Salt-Free Reduction of Transition Metal Complexes by Bis(trimethylsilyl)cyclohexadiene, -dihydropyrazine, and -4,4′-bipyridinylidene Derivatives". Accounts of Chemical Research 52 (3): 769–779. doi:10.1021/acs.accounts.8b00638. PMID 30794373. 
  6. Biradha, K.; Sarkar, M.; Rajput, L. (2006). "Crystal engineering of coordination polymers using 4,4′-bipyridine as a bond between transition metal atoms". Chemical Communications (40): 4169–79. doi:10.1039/B606184B. PMID 17031423.