2,2'-Bipyridine

2,2'-Bipyridine (bipy or bpy) CAS 366-18-7 is an organic compound with the formula C10H8N2. This off-white crystal powder is an important isomer of the bipyridine family. It is a bidentate chelating ligand, forming complexes with many transition metals. Ruthenium complex and platinum complexes of bipy exhibit intense luminescence, which may have practical applications.

2,2'-Bipyridine (bipy or bpy) CAS 366-18-7 is a bipyridine in which the two pyridine moieties are linked by a bond between positions C-2 and C-2'. It has a role as a ligand.

   2,2'-Bipyridine (bipy or bpy) CAS 366-18-7 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 complexation, the related N,N-heterocyclic ligand phenanthroline does not incur an enthalpic and entropic penalty, and thus its complexes tend to be more stable. With respective pKa's of 4.86 and 4.3 for their conjugate acids, phenanthroline and bipy are of comparable basicity.