4,4'-Bipyridine

4,4′-Bipyridine (abbreviated to 4,4′-bipy or 4,4′-bpy) is an organic compound with the formula (C₅H₄N)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.

4,4′-Bipyridine

4,4′-bipyridine
Names
Preferred IUPAC name 4,4′-Bipyridine
Identifiers
CAS Number	553-26-4 Y
3D model (JSmol)	Interactive image
Beilstein Reference	113176
ChEBI	CHEBI:30985 Y
ChEMBL	ChEMBL1374568
ChemSpider	10636 Y
ECHA InfoCard	100.008.216
EC Number	209-036-3
Gmelin Reference	3759
PubChem CID	11107
UNII	X4O2OD61CB
CompTox Dashboard (EPA)	DTXSID2027200
InChI InChI=1S/C10H8N2/c1-5-11-6-2-9(1)10-3-7-12-8-4-10/h1-8H N Key: MWVTWFVJZLCBMC-UHFFFAOYSA-N N
SMILES c1cnccc1-c2ccncc2
Properties
Chemical formula	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
Dipole moment	0 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). N verify (what is YN ?) Infobox references

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]

Reactions

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

NC₅H₄C₅H₄N + 2 Li + 2 Me₃SiCl → Me₃SiNC₅H₄C₅H₄NSiMe₃ + 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]