Bipyridine
Encyclopedia
Bipyridines are a family of chemical compound
s with the formula (C5H4N)2, which are formed by the coupling of two pyridine
rings. Six isomer
s 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
by increasing cAMP
, exerting positive inotropy and causing vasodilation. Inamrinone causes thrombocytopenia
. Milrinone
decreases survival in heart failure.
2,2'-bipyridine is a chelating
ligand
that forms complexes with most transition metal
ions. Many of these complexes have distinctive optical properties and some are of interest for analysis. 2,2'-Bipyridine is used in the manufacture of Diquat
.
4,4'-Bipyridine (4,4'-bipy) is mainly used as a precursor to the N,N-dimethyl-4,4'-bipyridinium dication commonly known as paraquat
. This species is redox
active, and its toxicity arises from its ability to interrupt biological electron transfer
processes. Because of its structure, 4,4'-bipyridine can bridge between metal centres to give coordination polymers
.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
s with the formula (C5H4N)2, which are formed by the coupling of two pyridine
Pyridine
Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one C-H group replaced by a nitrogen atom...
rings. Six isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
s of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine
2,2'-Bipyridine
2,2'-Bipyridine is a organic compound with the formula . This colorless solid, commonly abbreviated bipy or bpy , is an important isomer of the bipyridine family. It is a bidentate chelating ligand, forming complexes with many transition metals...
is a popular ligand in coordination chemistry and 4,4'-bipyridine
4,4'-Bipyridine
4,4'-Bipyridine is a bipyridine which is mainly used as a precursor to N,N'-dimethyl-4,4'-bipyridinium [2]2+, known as paraquat. This species is electroactive, and its toxicity arises from the ability of this dication to interrupt biological electron transfer...
is a precursor to the herbicide paraquat
Paraquat
Paraquat is the trade name for N,N′-dimethyl-4,4′-bipyridinium dichloride, one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings and animals...
. The bipyridines are colourless solids, which are soluble in organic solvents and slightly soluble in water.
The 3,4'-Bipyridine derivatives inamrinone and milrinone
Milrinone
Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...
are used occasionally for short term treatment of congestive heart failure. They inhibit phosphodiesterase
Phosphodiesterase
A phosphodiesterase is any enzyme that breaks a phosphodiester bond. Usually, people speaking of phosphodiesterase are referring to cyclic nucleotide phosphodiesterases, which have great clinical significance and are described below...
by increasing cAMP
Cyclic adenosine monophosphate
Cyclic adenosine monophosphate is a second messenger important in many biological processes...
, exerting positive inotropy and causing vasodilation. Inamrinone causes thrombocytopenia
Thrombocytopenia
Thrombocytopenia is a relative decrease of platelets in blood.A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease...
. Milrinone
Milrinone
Milrinone is a phosphodiesterase 3 inhibitor. It potentiates the effect of cyclic adenosine monophosphate .Milrinone also enhances contraction of the left ventricle by increasing Ca2+-ATPase activity on the cardiac sarcoplasmic reticulum...
decreases survival in heart failure.
2,2'-bipyridine
2,2'-bipyridine is a chelating
Chelation
Chelation is the formation or presence of two or more separate coordinate bonds between apolydentate ligand and a single central atom....
ligand
Ligand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
that forms complexes with most transition metal
Transition metal
The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...
ions. Many of these complexes have distinctive optical properties and some are of interest for analysis. 2,2'-Bipyridine is used in the manufacture of Diquat
Diquat
Diquat is a contact herbicide that produces desiccation and defoliation most often available as the dibromide, diquat dibromide. Brand names for this formulation include Aquacide, Dextrone, Preeglone, Deiquat, Detrone, Reglone, Reglon, Reglox, Ortho-Diquat and Weedtrine-D.Diquat is a non-selective...
.
4,4'-bipyridine
Paraquat
Paraquat is the trade name for N,N′-dimethyl-4,4′-bipyridinium dichloride, one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings and animals...
. This species is redox
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
active, and its toxicity arises from its ability to interrupt biological electron transfer
Electron transfer
Electron transfer is the process by which an electron moves from an atom or a chemical species to another atom or chemical species...
processes. Because of its structure, 4,4'-bipyridine can bridge between metal centres to give coordination polymers
Coordination polymers
A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by ligands, extending in an array. It can also be described as a polymer whose repeat units are coordination complexes...
.