Vanadyl acetylacetonate
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IUPAC name oxobis(2,4-pentanedionato)vanadium(IV) | |
Other names VO(acac)2, VO(pd)2 | |
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ECHA InfoCard | 100.019.628 |
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Properties | |
Chemical formula | C10H14O5V |
Molar mass | 265.157 g/mol |
Appearance | blue-green |
Density | 1.50 g/cm3 |
Melting point | 258 °C (496 °F; 531 K) |
Boiling point | 174 °C (345 °F; 447 K) at 0.2 torrs (27 Pa) |
Solubility in water | CHCl3, CH2Cl2, Benzene, CH3OH, CH3CH2OH |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references |
Vanadyl acetylacetonate is the chemical compound with the formula VO(acac)2, where acac– is the conjugate base of acetylacetone. It is a blue-green solid that dissolves in polar organic solvents. The coordination complex consists of the vanadyl group, VO2+, bound to two acac– ligands via the two oxygen atoms on each. Like other charge-neutral acetylacetonate complexes, it is not soluble in water.
Synthesis
The complex is generally prepared from vanadium(IV), e.g. vanadyl sulfate:[1]
- VOSO4 + 2 Hacac → VO(acac)2 + H2SO4
It can also be prepared by a redox reaction starting with vanadium pentoxide. In this reaction, some acetylacetone is oxidized to 2,3,4-Pentanetrione.[1]
Structure and properties
The complex has a square pyramidal structure with a short V=O bond. This d1 compound is paramagnetic. Its optical spectrum exhibits two transitions. It is a weak Lewis acid, forming adducts with pyridine and methylamine.[1]
Applications
It is used in organic chemistry as a catalyst for the epoxidation of allylic alcohols by tert-butyl hydroperoxide (TBHP). The VO(acac)2–TBHP system exclusively epoxidizes geraniol at the allylic alcohol position, leaving the other alkene of geraniol untouched. By comparison, m-CPBA, another epoxidizing agent, reacts with both alkenes, creating the products in a two to one ratio favoring reaction at the alkene away from the hydroxyl group. TBHP oxidizes VO(acac)2 to a vanadium(V) species which coordinates the alcohol of the substrate and the hydroperoxide, directing the epoxidation to occur at the alkene close to this coordination site.[2][3]
Biomedical aspects
Vanadyl acetylacetonate exhibits insulin mimetic properties, in that it can stimulate the phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3 (GSK-3).[4] It has also been shown inhibit tyrosine phosphatase (PTPase), PTPases[clarification needed] such as PTP1B, which dephosphorylates insulin receptor beta subunit, thus increasing its[clarification needed] phosphorylation, allowing for a prolonged activation of IRS-1, PKB, and GSK-3, allowing them to exert their anti-diabetic properties.[4]
External links
- Oxidations tutorial
References
- ^ a b c Rowe, Richard A.; Jones, Mark M. (1957). "Vanadium(IV) Oxy(acetylacetonate)". Inorganic Syntheses. Inorganic Syntheses. Vol. 5. pp. 113–116. doi:10.1002/9780470132364.ch30. ISBN 978-0-470-13236-4.
- ^ Itoh, Takashi; Jitsukawa, Koichiro; Kaneda, Kiyotomi; Teranishi, Shiichiro (1979). "Vanadium-catalyzed epoxidation of cyclic allylic alcohols. Stereoselectivity and stereocontrol mechanism". Journal of the American Chemical Society. 101 (1): 159–169. doi:10.1021/ja00495a027.
- ^ Rossiter, Bryant E.; Wu, Hsyueh-Liang; Hirao, Toshikazu (2007-03-15). "Vanadyl Bis(acetylacetonate)". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. doi:10.1002/047084289X.rv003m.pub2. ISBN 978-0-471-93623-7.
- ^ a b Mehdi, Mohamad Z.; Srivastava, Ashok K. (2005). "Organo-vanadium compounds are potent activators of the protein kinase B signaling pathway and protein tyrosine phosphorylation: Mechanism of insulinomimesis". Archives of Biochemistry and Biophysics. 440 (2): 158–164. doi:10.1016/j.abb.2005.06.008. PMID 16055077.
- v
- t
- e
- V(CO)6
- VF2
- VBr2
- VCl2
- VI2
- VO
- VS
- VSO4
- VBr3
- VCl3
- VF3
- VI3
- VN
- V2O3
- V2(SO4)3
- V2S3
Organovanadium(III) compounds |
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- VC
- VO2
- VOCl2
- V(S2)2
- VCl4
- VF4
Organovanadium(IV) compounds | |
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Vanadyl(IV) compounds |
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- V2O5
- VOCl3
- VOF3
- VO2F
- VF5
- VCl5
- NH4VO3
- VOPO4
- VO+2
Vanadyl(V) compounds |
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