What is "bipyridine"

n. (context organic compound English) Any of six isomeric bicyclic heterocycles consisting of two pyridine molecules directly linked; their derivatives have many industrial applications

Bipyridines also known as bipyridyls, dipyridyls, and dipyridines, are a family of chemical compounds with the formula (CHN), which are formed by the coupling of two pyridine rings. They are aromatic nitrogen heterocycles that form complexes with most transition metals. They interact with metals via both σ-donating nitrogen atoms and π-accepting molecular orbitals. Bipyridines figure prominently in studies of electron and energy transfer, supramolecular and materials chemistry, and catalysis.

Six isomers of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine is a popular ligand in coordination chemistry and 4,4'-bipyridine is a precursor to the herbicide paraquat. The bipyridines are colourless solids, which are soluble in organic solvents and slightly soluble in water.

The 3,4'-Bipyridine derivatives inamrinone and milrinone are used occasionally for short term treatment of congestive heart failure. They inhibit phosphodiesterase and thus increasing cAMP, exerting positive inotropy and causing vasodilation. Inamrinone causes thrombocytopenia. Milrinone decreases survival in heart failure.