Search results for "Ketone"
showing 10 items of 337 documents
Electron paramagnetic resonance, ENDOR and TRIPLE resonance study of some 9,10-anthraquinone radicals in solution
1992
EPR, ENDOR and TRIPLE resonance spectra were recorded for 1,8-dihydroxy-3-methyl-9,10-anthraquinone and 9,10-anthraquinone-2-carboxylic acid anion radicals and the 9,10-anthraquinol-2-carboxylic acid cation radical. EPR spectra were recorded for the 5,8-dideuterio-1,4-dideuterioxy-9,10-anthraquinone anion radical, the 6,7-dideuterio-1,4-dideuterioxy-9,10-anthraquinone anion radical and the 1,4-dihydroxy-9,10-anthraquinol cation radical. The coupling contants of the 1,4-dihydroxy-9,10-anthraquinone anion radical were assigned by deuteriation.
Heterobimetallic single-source precursors for MOCVD. Synthesis and characterization of volatile mixed ligand complexes of lanthanides, barium and mag…
1999
Several heterobimetallic complexes of general formula [(M 1 Q) m M 2 (dik) n ], where (M 1 Q) is Cu(salen) or Ni(salen) and M 2 (dik) n is a lanthanide tris(β-diketonate) or an alkali-earth element bis(β-diketonate) with more or less fluorinated diketonato(-) ligands, have been prepared and structurally characterized. Some of them were submitted to thermal and mass spectrometry analyses, and to isothermal vacuum sublimation tests, in view of their potential use as MOCVD single-source precursors for the deposition of heterobimetallic materials. The study stresses upon the influence of the nature of the diketone. of the M 2 cation, and of chemical modification of the salen ligand on the therm…
Neue chemotherapeutisch-aktive 4-trifluormethylpyrimidine
1993
Abstract Condensation of N -(2-hydroxyethyl)- N -methylguanidine sulfate with various β-diketonesbearing 1,1,1-trifluoromethyl substituents leads to 2-[ N -(2-hydroxyethyl)-methylamino]-4-trifluoromethylpyrimidine derivatives. These compounds exhibit antimycotic, trichomonazide and anti-HIV properties.
The reduction mechanism of the CO group.
2001
A detailed study of the electrochemical reduction of benzil in aqueous medium between H0=−5 and pH 11 is presented. A global 2e−, 3H+ or 2e−, 2H+ surface reaction leads to cis and trans endiols. Analysis, using the theory of the square schemes with protonations at equilibrium, shows that in all the pH range the reaction is controlled by the second electron uptake, the paths being successively H+, e− and e−, H+. The electrochemical reaction is followed by surface isomerizations whose rate constants vary from 7 to 200 s−1 for the trans/cis and from 1 to 2000 s−1 for the cis/trans transformations.
Electrochemical synthesis of 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles and (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP com…
2009
Abstract Cathodic reductions of 2,2′-furils in the presence of N-arylcarbonimidoyl dichlorides lead to 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles in high yields, along with minor amounts of (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP density functional theory methods have been applied to the determination of molecular geometries and to study the topomerization mechanism of aryliminodioxoles. The molecular structure of (E)-1,2-di(2-furyl)vinylene bis[N-(2-chloro-4-methylphenyl)chloroformimidate] has been determined by X-ray crystallography and compared with the calculated structure.
The heterodinuclear iron(III) and copper(II) molecule Cu(salen)Fe(acac)2NO3 and its iron precursor Fe(acac)2NO3. Synthesis, magnetic susceptibility, …
1992
Abstract The synthesis, EPR, magnetic and Mossbauer properties of two iron(III) complexes are reported. The heterodinuclear iron(III)-copper(II) complex Cu(salen)Fe(acac)2NO3 is obtained as an adduct from the reaction of the two mononuclear moieties, the Cu(salen) molecule and the mononuclear iron(III) molecule Fe(acac)2NO3 acting as a precursor of the dinuclear unit. The latter molecule itself has been prepared by ligand substitution from the tris-acetylacetonate Fe(acac)3. The dinuclear complex is characterized by comparing the properties of the mono- and the dinuclear complex. Fe(acac)2NO3 is identified from its typical IR spectrum with the main nitrate vibrations at 1380, 1250 and 1010 …
Migration of bidentate anionic ligands in binuclear compounds derived from 1,2-bis(imino)propyl-palladium(II) complexes
1983
Abstract The complexes [Pd(AB){C(NR)CMeNR}(PPh3)] (I; AB = 2,4-pentanedionate, N-methylsalicylaldiminate, pyrrole-2-N-methylaldiminate; R = p-C6H4OMe) react with ‘MCl2’ (‘MCl2’ = CoCl2, NiCl2, CuCl2, ZnCl2, [PdCl2(NCMe)2], K[PtCl3(CH2CH2)]) to give either the binuclear adducts [(PPh3)(AB)Pd{C(NR)CMeNR}MCl2] (II) or the zwitterionic isomers [(PPh3)Cl2Pd{C( NR)CMeNR}M (AB)] (III) depending on the nature of the metal M and of the anionic ligand AB. The formation of products III is accounted for in terms of an intramolecular migration of ligands between the two metal centers Pd and M of the initially formed MCl2 adducts II.
Über die Synthese methylsubstituierter P-Oligopenylene. 5. Mitteilung
1959
Unsubstituierte p-Oligophenylene sind sehr schwer loslich. Die Loslichkeit dieser substanzen kann durch Substitution mit Methylgruppen verbessert werden. Fur die Synthese methylsubstituierter p-Oligophenylence wurden verschiedene Verfahren herangezogen. Durch ULIMANN-Kondensation entsprechender Jodaryle konnten zwei substitutionsisomere Tettamethyl-p-quaterphenyle, ein Tetramethoxy-p-quaterphenyl und ein Tetramethyl-p-sexiphenyl synthetisiert werden. Uber die Carbonyladdition aromatischer metallorganischer Verbindungen an cyclische Diketone wurden uber hydroaromatische Zwischenstufen ein Dimethyl-p-terphenyl, ein Tetramethyl-p- quinquiphenul, zwei substitutionsisomere Dimethyl-p-quaterpheny…
Oligomere aus gleichsinnig angeordneten Chalkon-Bausteinen
1999
The cross-conjugated oligomers 1a–d, which contain up to eight alternately arranged chalcone building blocks, were prepared by stereoselective condensation reactions of formyl and acetyl components. The synthetic sequence started with 1,4-dibromo-2,5-dipropoxybenzene (2). Bouveault reactions with DMF and DMA yielded the aldehydes 3 and 6 and the ketones 7 and 10. After the protection of the carbonyl group (3 4 and 7 8), a further Bouveault reaction led to monoprotected dialdehyd 5 and diketone 9, respectively. Repetitive condensation reactions starting with the acetophenone derivative 11 and 5 furnished the aldehyde 12, the ketone 13 and the aldehyde 14. In the final step the target compoun…
New structural motifs in Mn cluster chemistry from the ketone/gem-diol and bis(gem-diol) forms of 2,6-di-(2-pyridylcarbonyl)pyridine: {MnII4MnIII2} a…
2016
The employment of the tripyridyl/diketone ligand 2,6-di-(2-pyridylcarbonyl)pyridine [(py)CO(py)CO(py)], in conjunction with azides (N3−), in Mn cluster chemistry has afforded the mixed-valence (II/III) complexes [MnII4MnIII2(N3)6Cl4(L1)2(DMF)4] (1) and [MnII4MnIII6O2(N3)12(L1)2(L2H)2(DMF)6] (2) in good yields. The resulting ligands L12− and L2H3− are the dianion and trianion of the ketone/gem-diol (L1H2) and bis(gem-diol) (L2H4) forms of (py)CO(py)CO(py), respectively, as derived from the metal-assisted hydrolysis of the parent dicarbonyl organic compound. Under the same synthetic conditions (i.e., reaction solvents, temperature and stirring time), the chemical identity of the two complexes…