Phenanthroline
Encyclopedia
Phenanthroline is a heterocyclic organic compound
. As a bidentate ligand
in coordination chemistry, it forms strong complexes with most metal ions. In terms of its coordination properties, phen is similar to 2,2'-bipyridine
(bipy).
s of glycerol
with o-phenylenediamine
, catalyzed by sulfuric acid
, and an oxidizing agent, traditionally aqueous
arsenic acid
or nitrobenzene
. Dehydration of glycerol
gives acrolein
which condenses with the amine
followed by a cyclization.
of metallopeptidases, with one of the first observed instances reported in carboxypeptidase A. Inhibition of the enzyme occurs by removal and chelation of the metal ion required for catalytic activity, leaving an inactive apoenzyme. 1,10-Phenanthroline targets mainly zinc metallopeptidases, with a much lower affinity for calcium.
," is used for the photometric
determination of Fe(II). It is used as a redox
indicator
with standard potential +1.06 V. The reduced ferrous form has a deep red colour and the oxidised form is light-blue. Ferroin is used as a cell permeable inhibitor
for metalloproteases in cell biology.
The pink complex [Ni(phen)3]2+ has been resolved into its Δ and Λ isomers. The analogous [Ru(phen)3]2+ has long been known to be bioactive.
Grignard reagents may be similarly titrated.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
. As a bidentate 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...
in coordination chemistry, it forms strong complexes with most metal ions. In terms of its coordination properties, phen is similar to 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...
(bipy).
Synthesis
Phenanthroline may be prepared by two successive Skraup reactionSkraup reaction
The Skraup synthesis is a chemical reaction used to synthesize quinolines. It is named after the Czech chemist Zdenko Hans Skraup . In the archetypal Skraup, aniline is heated with sulfuric acid, glycerol, and an oxidizing agent, like nitrobenzene to yield quinoline.In this example, nitrobenzene...
s of glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
with o-phenylenediamine
O-Phenylenediamine
o-Phenylenediamine is a organic compound with the formula C6H42. This aromatic diamine is an important precursor to many heterocyclic compounds...
, catalyzed by sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
, and an oxidizing agent, traditionally aqueous
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
arsenic acid
Arsenic acid
Arsenic acid is the chemical compound with the formula H3AsO4. More descriptively written as AsO3, this colorless acid is the arsenic analogue of phosphoric acid. Arsenate and phosphate salts behave very similarly. Arsenic acid as such has not been isolated, but only found in solution where it...
or nitrobenzene
Nitrobenzene
Nitrobenzene is an organic compound with the chemical formula C6H5NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale as a precursor to aniline. Although occasionally used as a flavoring or perfume...
. Dehydration of glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
gives acrolein
Acrolein
Acrolein is the simplest unsaturated aldehyde. It is produced widely but is most often immediately reacted with other products due to its instability and toxicity...
which condenses with the amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
followed by a cyclization.
Peptidase inhibitor
1,10-Phenanthroline is an inhibitorEnzyme inhibitor
An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...
of metallopeptidases, with one of the first observed instances reported in carboxypeptidase A. Inhibition of the enzyme occurs by removal and chelation of the metal ion required for catalytic activity, leaving an inactive apoenzyme. 1,10-Phenanthroline targets mainly zinc metallopeptidases, with a much lower affinity for calcium.
Ferroin and analogues
The complex [Fe(phen)3]2+, called "ferroinFerroin
Ferroin is the chemical compound with the formula [Fe3]SO4, where o-phen is an abbreviation for 1,10-phenanthroline, a bidentate ligand. The term "ferroin" is used loosely and includes salts of other anions such as chloride.-Redox indicator:...
," is used for the photometric
Spectrophotometry
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength...
determination of Fe(II). It is used as a redox
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
indicator
Redox indicator
A redox indicator is an indicator that undergoes a definite color change at a specific electrode potential....
with standard potential +1.06 V. The reduced ferrous form has a deep red colour and the oxidised form is light-blue. Ferroin is used as a cell permeable inhibitor
Enzyme inhibitor
An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...
for metalloproteases in cell biology.
The pink complex [Ni(phen)3]2+ has been resolved into its Δ and Λ isomers. The analogous [Ru(phen)3]2+ has long been known to be bioactive.
Related ligands
In the related compound "bathophenanthroline," the 4 and 7 positions are substituted by phenyl groups.As an indicator for alkyl lithium reagents
Alkyl lithium reagents form deeply colored derivatives with phenanthroline. The alkyl lithium content of solutions can be determined by treatment of such reagents with small amounts of phenanthroline (ca. 1 mg) followed by titration with alcohols to a colourless endpoint.Grignard reagents may be similarly titrated.
External links
- The MEROPSMeropsMerops may refer to:* Merops , a genus of bee-eaters.* MEROPS, an on-line database for peptidases.It may also refer to several figures from Greek mythology:* King of Ethiopia, husband of Clymene, who lay with Helios and bore Phaethon...
online database for peptidases and their inhibitors: 1,10-Phenanthroline