1,10-Phenanthroline
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| Names | |
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| IUPAC name
1,10-phenanthroline
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.000.572 |
| RTECS number |
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CompTox Dashboard (EPA)
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| Properties | |
| C12H8N2 | |
| Molar mass | 180.21 g/mol |
| Appearance | colourless crystals |
| Density | 1.31 g/cm3 |
| Melting point | 117 °C (243 °F; 390 K) |
| moderate | |
| Solubility in other solvents | acetone
ethanol |
| Acidity (pKa) | 4.86 (phenH+)[1] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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mild neurotoxin, strong nephrotoxin, and powerful diuretic |
| Related compounds | |
Related compounds
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2,2'-bipyridine ferroin phenanthrene |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. It is used as a ligand in coordination chemistry, it forms strong complexes with most metal ions.[2]
Synthesis
Phenanthroline may be prepared by two successive Skraup reactions of glycerol with o-phenylenediamine, catalyzed by sulfuric acid, and an oxidizing agent, traditionally aqueous arsenic acid or nitrobenzene.[3] Dehydration of glycerol gives acrolein which condenses with the amine followed by a cyclization.
Coordination chemistry
In terms of its coordination properties, phen is similar to 2,2'-bipyridine (bipy) but binds metals more tightly since the chelating nitrogen donors are preorganized.
Many homoleptic complexes are known. Particularly well studied is [Fe(phen)3]2+, called "ferroin." It was used for the photometric determination of Fe(II).[4] 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.[5] The pink complex [Ni(phen)3]2+ has been resolved into its Δ and Λ isomers.[6] Copper(I) forms [Cu(phen)2]+, which is luminescent.[7][8]
Bioinorganic chemistry
The ferroin analogue [Ru(phen)3]2+ has long been known to be bioactive.[9]
1,10-Phenanthroline is an inhibitor of metallopeptidases, with one of the first observed instances reported in carboxypeptidase A.[10] 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.[11]
Related phen ligands
A variety of substituted derivatives of phen have been examined as ligands.[8] Neocuproine, 2,9-dimethyl-1,10-phenanthroline, is a bulky ligand. In "bathophenanthroline," the 4 and 7 positions are substituted by phenyl groups. The more electron-rich phenanthroline ligand is 3,4,7,8-tetramethyl-1,10-phenanthroline.[2]
Numbering for 1,10-phenanthroline derivatives.
As an indicator for alkyllithium reagents
Alkyllithium reagents form deeply colored derivatives with phenanthroline. The alkyllithium 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.[12] Grignard reagents may be similarly titrated.[13]
References
- ^ Durand, J., et al., "Long-Lived Palladium Catalysts for Co/Vinyl Arene Polyketones Synthesis: A Solution to Deactivation Problems", Chemistry – A European Journal 2006, volume 12, 7639-7651. doi:10.1002/chem.200501047
- ^ a b C.R. Luman, F.N. Castellano "Phenanthroline Ligands" in Comprehensive Coordination Chemistry II, 2003, Elsevier. ISBN 978-0-08-043748-4.
- ^ B. E. Halcrow; W. O. Kermack (1946). "43. Attempts to find new antimalarials. Part XXIV. Derivatives of o-phenanthroline (7 : 8 : 3′ : 2′-pyridoquinoline)". J. Chem. Soc.: 155–157. doi:10.1039/jr9460000155.
- ^ Belcher, R. "Application of chelate Compounds in Analytical Chemistry" Pure and Applied Chemistry, 1973, volume 34, pages 13-27.
- ^ Bellér, G. B.; Lente, G. B.; Fábián, I. N. (2010). "Central Role of Phenanthroline Mono-N-oxide in the Decomposition Reactions of Tris(1,10-phenanthroline)iron(II) and -iron(III) Complexes". Inorganic Chemistry. 49: 3968–3970. doi:10.1021/ic902554b. PMID 20415494.
- ^ George B. Kauffman, Lloyd T. Takahashi (1966). "Resolution of the tris-(1,10-Phenanthroline)Nickel(II) Ion". Inorg. Synth. 5: 227–232. doi:10.1002/9780470132395.ch60.
- ^ Armaroli, N., "Photoactive Mono- and Polynuclear Cu(I)-Phenanthrolines. A Viable Alternative to Ru(Ii)-Polypyridines?", Chemical Society Reviews 2001, volume 30, 113-124.doi:10.1039/b000703j
- ^ a b Pallenberg, A. J.; Koenig, K. S.; Barnhart, D. M., "Synthesis and Characterization of Some Copper(I) Phenanthroline Complexes", Inorg. Chemistry 1995, volume 34, 2833-2840. doi:10.1021/ic00115a009
- ^ F. P. Dwyer; E. C. Gyarfas; W. P. Rogers; J. H. Koch (1952). "Biological Activity of Complex Ions". Nature. 170 (4318): 190–191. doi:10.1038/170190a0. PMID 12982853.
- ^ Felber, JP, Coombs, TL & Vallee, BL (1962). "The mechanism of inhibition of carboxypeptidase A by 1,10-phenanthroline". Biochemistry. 1 (2): 231–238. doi:10.1021/bi00908a006. PMID 13892106.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Salvesen, GS; Nagase, H (2001). "Inhibition of proteolytic enzymes". Proteolytic enzymes: a practical approach, 2 edn. 1: 105–130.
{{cite journal}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help) - ^ Paul J. Fagan and William A. Nugent (1998). "1-Phenyl-2,3,4,5-Tetramethylphosphole". Organic Syntheses; Collected Volumes, vol. 9, p. 653.
- ^ Ho-Shen Lin; Leo A. Paquette (1994). "A Convenient Method for Determining the Concentration of Grignard Reagents". Synth. Commun. 24 (17): 2503–2506. doi:10.1080/00397919408010560.