A molecularly imprinted electrochemiluminescence sensor based on the mimetic enzyme catalytic effect for ultra-trace Ni2+ determination Bin Yang,a Jianping Li, a Lianming Zhanga and Guobao Xub a College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, PR China. Spectroscopic characterization of the polycrystalline copper(I) di-n-butyldithlophosphate cluster - Cu 8 S 2 P(O-n-Bu) 2 6 (mu 8-S): Solid-state 31 P CP/MAS and static 65 Cu NMR studies, Inorg. SYNTHESIS AND STRUCTURE OF CONDENSATION PRODUCT OF DIMETHYLGLYOXIME ON GOLD MATRIX P. Bologa., Yu. Simonov., and J. (H2DMG) molecules on the. Suitable for dissolution of 1. The characteristic peak for NH- group (near 2.0 ppm) in NMR spectrum was not found. This confirms the fact of deprotonation of the. 1H NMR spectrum of urine from the patient (A) and from an age-matched man (B). Conversion of choline into glycine via DMG. Enzymes involved in the pathway are: 1, choline dehydrogenase; 2, betaine aldehyde dehydrogenase; 3, betaine-homocysteine methyltransferase; and 4, sarcosine dehydrogenase. 460 Moolenaar et al.: DMGDH Deficiency.
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3D model (JSmol) |
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741937 | |
ChEBI |
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ChEMBL | |
ChemSpider |
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ECHA InfoCard | 100.004.214 |
EC Number | |
2537 | |
KEGG | |
PubChemCID | |
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UNII | |
UN number | 2310 |
CompTox Dashboard(EPA) | |
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Properties | |
C5H8O2 | |
Molar mass | 100.117 g·mol−1 |
Density | 0.975 g/mL[1] |
Melting point | −23 °C (−9 °F; 250 K) |
Boiling point | 140 °C (284 °F; 413 K) |
16 g/100 mL | |
-54.88·10−6 cm3/mol | |
Hazards | |
GHS pictograms | |
GHS Signal word | Danger |
H226, H302, H311, H320, H331, H335, H341, H370, H402, H412 | |
P201, P202, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P281, P301+312, P302+352, P303+361+353, P304+340, P305+351+338, P307+311, P308+313, P311, P312 | |
NFPA 704 (fire diamond) | |
Flash point | 34 °C (93 °F; 307 K) |
340 °C (644 °F; 613 K) | |
Explosive limits | 2.4–11.6% |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
verify (what is ?) | |
Infobox references |
Acetylacetone is an organic compound with the formula CH3COCH2COCH3. It is a colorless liquid, classified as a 1,3-diketone. It exists in equilibrium with a tautomer CH3C(O)CH=C(OH)CH3. These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications.[2] It is a colorless liquid that is a precursor to acetylacetonate anion (commonly abbreviated acac−), a bidentateligand. It is also a building block for the synthesis of heterocyclic compounds.
- 1Properties
- 3Reactions
Properties[edit]
Tautomerism[edit]
The keto and enoltautomers of acetylacetone coexist in solution. The enol form has C2vsymmetry, meaning the hydrogen atom is shared equally between the two oxygen atoms.[3] In the gas phase, the equilibrium constant, Kketo→enol, is 11.7, favoring the enol form. The two tautomeric forms can be distinguished by NMR spectroscopy, IR spectroscopy and other methods.[4][5]
Solvent | Kketo→enol |
---|---|
Gas phase | 11.7 |
Cyclohexane | 42 |
Toluene | 10 |
THF | 7.2 |
DMSO | 2 |
Water | 0.23 |
The equilibrium constant tends to be high in nonpolar solvents; the keto form becomes more favorable in polar, hydrogen-bonding solvents, such as water.[6] The enol form is a vinylogous analogue of a carboxylic acid.
Acid–base properties[edit]
solvent | T/°C | pKa[7] |
---|---|---|
40% ethanol/water | 30 | 9.8 |
70% dioxane/water | 28 | 12.5 |
80% DMSO/water | 25 | 10.16 |
DMSO | 25 | 13.41 |
Acetylacetone is a weak acid:
- C5H8O2 ⇌ C
5H
7O−
2 + H+
IUPAC recommended pKa values for this equilibrium in aqueous solution at 25 °C are 8.99 ± 0.04 (I = 0), 8.83 ± 0.02 (I = 0.1 M NaClO4) and 9.00 ± 0.03 (I = 1.0 M NaClO4; I = Ionic strength).[8] Values for mixed solvents are available. Very strong bases, such as organolithium compounds, will deprotonate acetylacetone twice. The resulting dilithio species can then be alkylated at C-1.
Preparation[edit]
Acetylacetone is prepared industrially by the thermal rearrangement of isopropenyl acetate.[9]
- CH2(CH3)COC(O)Me → MeC(O)CH2C(O)Me
Laboratory routes to acetylacetone begin also with acetone. Acetone and acetic anhydride upon the addition of boron trifluoride (BF3) catalyst:[10]
- (CH3CO)2O + CH3C(O)CH3 → CH3C(O)CH2C(O)CH3
A second synthesis involves the base-catalyzed condensation of acetone and ethyl acetate, followed by acidification:[10]
- NaOEt + EtO2CCH3 + CH3C(O)CH3 → NaCH3C(O)CHC(O)CH3 + 2 EtOH
- NaCH3C(O)CHC(O)CH3 + HCl → CH3C(O)CH2C(O)CH3 + NaCl
Because of the ease of these syntheses, many analogues of acetylacetonates are known. Some examples include C6H5C(O)CH2C(O)C6H5 (dbaH) and (CH3)3CC(O)CH2C(O)CC(CH3)3. Hexafluoroacetylacetonate is also widely used to generate volatile metal complexes.
Reactions[edit]
Condensations[edit]
Acetylacetone is a versatile bifunctional precursor to heterocycles because both keto groups undergo condensation. Hydrazine reacts to produce pyrazoles. Urea gives pyrimidines. Condensation with two aryl- and alkylamines to gives NacNacs, wherein the oxygen atoms in acetylacetone are replaced by NR (R = aryl, alkyl).
Lol malzahar does no dmg. They only scale with your attack damage, unfortunately.A voidlings has 200 + (50 × level) health and 20 + (5 × level) + (100%bonus AD) attack damage. Here's the a better description of the ability in full.
Nmr Of Cu(dmg)2 Time
Coordination chemistry[edit]
A ball-and-stick model of VO(acac)2
The acetylacetonate anion, acac−, forms complexes with many transition metal ions. A general method of synthesis is to treat a metal salt with acetylacetone in the presence of a base:[11]
- MBz + z Hacac ⇌ M(acac)z + z BH
Both oxygen atoms bind to the metal to form a six-membered chelate ring. In some cases the chelate effect is so strong that no added base is needed to form the complex.
Biodegradation[edit]
Enzymatic breakdown: The enzyme acetylacetone dioxygenase cleaves the carbon-carbon bond of acetylacetone, producing acetate and 2-oxopropanal. The enzyme is iron(II)-dependent, but it has been proven to bind to zinc as well. https://slvlrq.weebly.com/musically-download-mac.html. Acetylacetone degradation has been characterized in the bacterium Acinetobacter johnsonii.[12]
Convertir iso en dmg. Download Program Link:(Click the link, wait 5 seconds, skip ad, download your file)-Alternative Link-(Click the link, wait 5 seconds, skip ad, download your file)Activation Key for Full Version:User Name: monalisa2Serial Key:jUkRtAQAFQIQE1FuWPvqMb7lJ1RFCK1vTn3nMvE3N2kPBjrwNP&BkMLcnNu1fAQjqTogcVcEtkw5crBHIn0aN4JK&vfUlWQxAICwqmfSeDP1yhKgftGY4nBmWveR0jSDQDr2F1lR9Krpiyp60SO73ySj3tRHl&kkl1IMwDZSKCheck Out This Video Link Below To Learn How To Create Multi-Boot USB Flash Drive:««For More Videos »»©omment^ ®ate^ $ubscribe^.
- C5H8O2 + O2 → C2H4O2 + C3H4O2
References[edit]
- ^'05581: Acetylacetone'. Sigma-Aldrich.
- ^Thomas M. Harris (2001). '2,4‐Pentanedione'. e-EROS Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rp030.
- ^Caminati, W.; Grabow, J.-U. (2006). 'The C2v Structure of Enolic Acetylacetone'. J. Am. Chem. Soc.128 (3): 854–857. doi:10.1021/ja055333g. PMID16417375.
- ^Manbeck, Kimberly A.; Boaz, Nicholas C.; Bair, Nathaniel C.; Sanders, Allix M. S.; Marsh, Anderson L. (2011). 'Substituent Effects on Keto–Enol Equilibria Using NMR Spectroscopy'. J. Chem. Educ.88 (10): 1444–1445. doi:10.1021/ed1010932.
- ^Yoshida, Z.; Ogoshi, H.; Tokumitsu, T. (1970). 'Intramolecular hydrogen bond in enol form of 3-substituted-2,4-pentanedione'. Tetrahedron. 26: 5691–5697. doi:10.1016/0040-4020(70)80005-9.
- ^Reichardt, Christian (2003). Solvents and Solvent Effects in Organic Chemistry (3rd ed.). Wiley-VCH. ISBN3-527-30618-8.
- ^IUPAC SC-Database A comprehensive database of published data on equilibrium constants of metal complexes and ligands
- ^Stary, J.; Liljenzin, J. O. (1982). 'Critical evaluation of equilibrium constants involving acetylacetone and its metal chelates'(PDF). Pure and Applied Chemistry. 54 (12): 2557–2592. doi:10.1351/pac198254122557.
- ^Siegel, Hardo; Eggersdorfer, Manfred (2002). 'Ketones'. Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a15_077.
- ^ abC. E. Denoon, Jr. 'Acetylacetone'. Organic Syntheses.; Collective Volume, 3, p. 16
- ^O'Brien, Brian. 'Co(tfa)3 & Co(acac)3 handout'(PDF). Gustavus Adolphus College.
- ^Straganz, G.D.; Glieder, A.; Brecker, L.; Ribbons, D.W.; Steiner, W. (2003). 'Acetylacetone-cleaving enzyme Dke1: a novel C–C-bond-cleaving enzyme from Acinetobacter johnsonii'. Biochem. J. 369 (3): 573–581. doi:10.1042/BJ20021047. PMC1223103. PMID12379146.
External links[edit]
Nmr Of Cu(dmg)2 Science
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