Other name: 2,2'-Bipyridine; 2,2’-Bipyridyl; 2,2’-Dipyridyl
Appearance: off-white crystal powder
Purity: 98%min.; 99%min.
Package: 100g, 1Kg, 5Kg, 25Kg
2-(2-Pyridyl)pyridine is colorless to off-white crystal powder, an important isomer of the bipyridine family. It is a bidentate chelating ligand, forming complexes with many transition metals.
2-(2-Pyridyl)pyridine is prepared by the dehydrogenation of pyridine using Raney nickel
2C5H5N → (C5H4N)2 + H2
Although uncoordinated bipyridine is often drawn with its nitrogen atoms in cis conformation, the lowest energy conformation both in solid state and in solution is in fact coplanar, with nitrogen atoms in trans position. Protonated bipyridine adopts a cis conformation. Upon binding to metal ions the related N,N-heterocyclic ligand phenanthroline does not incur an enthalpic and entropic penalty, and thus its complexes tend to be more stable.
Bipyridine complexes absorb intensely in the visible part of the spectrum. The electronic transitions are attributed to metal-to-ligand charge transfer (MLCT). In the "tris(bipy) complexes" three bipyridine molecules coordinate to a metal ion, written as [M(bipy)3]n+ (M = metal ion; Cr, Fe, Co, Ru, Rh and so on; bipy = 2,2′-bipyridine). These complexes have six-coordinated, octahedral structures and two enantiomers as follows:
These and other homoleptic tris-2,2′-bipy complexes of many transition metals are electroactive. Often, both the metalcentred and ligand centred electrochemical reactions are reversible one-electron reactions that can be observed by cyclic voltammetry. Under strongly reducing conditions, most tris(bipy) complexes can be reduced to neutral derivatives containing bipy− ligands.
The following 2,2'-bipyridine derivtives are available from UCHEM.
2,2'-Bipyridine-5-carboxylic acid CAS: 1970-80-5
2-Chloro-2,2'-bipyridine CAS: 13040-77-2
6-Bromo-2,2’-bipyridine CAS: 10495-73-5
Methyl 2,2'-bipyridine-6-carboxylate CAS: 203573-76-6
2,2'-Bipyridine-6-carboxylic acid CAS: 4392-87-4
2,2'-Bipyridine-4-carboxylic acid CAS:1748-89-6
2,2'-Bipyridyl-3,3'-dicarboxylic acid CAS:4433-01-6
2,2'-Bipyridine-3,3'-dicarboxylic acid dimethyl ester CAS: 39775-31-0
6,6'-Dimethyl-2,2'-bipyridine CAS: 4411-80-7
2,2'-Bipyridine-6,6'-dicarboxylic acid CAS:4479-74-7
2,2'-Bipyridine-5,5'-dicarboxaldehyde CAS: 135822-72-9
4,4'-Dinonyl-2,2'-bipyridine CAS: 142646-58-0
Dimethyl 2,2'-bipyridine-4,4'-dicarboxylate CAS: 71071-46-0