Interaction between 1,2-dimethyl-3-hydroxypyrid-4-one and europium(III)

The interaction of the clinically used 1,2-dimethyl-3-hydroxypyrid-4-one with trivalent europium Eu(III), was investigated by using potentiometric and spectroscopic methods. The stability constants of the EuL_n ⁽³⁻ⁿ⁾⁺ complexes determined by spectroscopic and potentiometric measurements were found to be log β₁₁ = 6.5±0.3 and log β₁₂ = 12.0±0.5. However, at pH ≥ 5, hydrolysis of the Eu-L complexes starts, resulting in the formation of needle-type, yellow crystals. The low solubility of the Eu-L complexes in the neutral pH range is disadvantageous with respect to the use of deferiprone as chelating agent for decorporation of trivalent f-elements.     

HPLC-based measurement of the chelator 1,2-dimethyl-3-hydroxy-pyrid-4-one (L1) and its iron complex for pharmacokinetic studies in humans

An improved HPLC based method to assay the oral active iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1, CP20) in serum and urine is described. The L1 peak has been well separated from other endogenous compounds, allowing the exact determination of the drug in both biological fluids. Moreover urinary iron excretion due to L1 therapy has been monitored by measuring urine Fe-(L1)₃ complex concentrations using reverse phase HPLC and subsequent detection at 450 nm. In patients and normal volunteers receiving this drug there is a good correlation between urine iron excretion measured by AAS and by the HPLC based method.     

Complex formation of uranium(VI) with 4-hydroxy-3-methoxybenzoic acid and related compounds

Summary The complex formation of uranium(VI) with 4-hydroxy-3-methoxybenzoic acid as well as with benzoic acid and 4-hydroxybenzoic acid was studied. In aqueous solution weak carboxylic 1 : 1 complexes, are formed in which the carboxyl group is bidentately coordinated to the metal atom. The logarithmic stability constants of these complexes regarding the reaction of the uranyl ion with the single charged anion of the respective ligands are 2.78±0.02, 2.68±0.04, and 2.71±0.04 at an ionic strength of 0.1 mol/l (NaClO₄) and at 25 °C. Bis(4-hydroxy-3-methoxybenzoato)dioxouranium(VI) was obtained as a crystalline compound if the concentrations of the starting components for the synthesis are increased. The monoclinic compound has a reflections-rich X-ray powder diffraction pattern. The lattice constants are a = 13.662(9) ?, b = 21.293(7) ?, c = 11.213(3) ?, b = 107.49(4), and V = 3111(2) ?.³     

4-[（Furan-2-ylmethylene）-amino]-1,5- dimethyl-1,2-dihyl-1,2-dihydo-pyrazol-3-one

1 INTRODUCTION Antipyrine (2,3-dimethyl-1-phenyl-5-pyrazolone) and its derivatives exhibit a wide range of biological activities and applications[1～3]. Antipyrine shows mi- nimal protein binding and is rapidly and complete- ly absorbed from the gastrointestinal tract and exten- sively metabolized by the cytochrome P450 liver en- zymes[4]. Estimates of half-life and systemic clear- ance of antipyrine have been used for the in vivo as- sessment of hepatic drug oxidation in different spe- c…     

Structure of 1-phenyl-1-thioxo-2,5-dimethyl-3-morpholinomethyl-phosphorinan-4-one

Chemical Sciences Institute, Kazakh Academy of Sciences. Institute for Heteroorganic Compounds, USSR Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 1, pp. 184–186, January–February, 1990.     

Extraction of chromium(VI) with 4-methyl-3-pentene-2-one and subsequent photometric determination as diphenylcarbazide complex

Summary A rapid and sensitive method is developed for the solvent extraction of chromium(VI) with mesityl oxide. Chromium(VI) is extracted with pure mesityl oxide from 1 M HCl containing 2.5 M KCl as salting-out agent. The metal from the organic phase is stripped with dilute ammonia and determined photometrically as its dephenylcarbazide complex at 540 nm. Chromium(VI) can be extracted in presence of a large number of ions. Only 30 min are required for complete separation and determination. Average recovery was 98.6 ± 1.4%, the standard deviation ± 1.3% (14.9 g of Cr).

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Extraktion von Chrom(VI) mit 4-Methyl-3-penten-2-on und anschlieende photometrische Bestimmung als Diphenylcarbazidkomplex

Zusammenfassung Chrom wird mit reinem Mesityloxid aus 1 M salzsaurer, 2,5 M KCl enthaltender Lösung extrahiert, mit Ammoniaklösung aus der organischen Phase entfernt und photometrisch als Diphenylcarbazidkomplex bei 540 nm bestimmt. Zahlreiche Fremdionen stören die Extraktion nicht. Für Abtrennung und Bestimmung werden 30 min benötigt. Im Durchschnitt wurden 98,6 ± 1,4 % wiedergefunden. Die Standard-abweichung betrug ± 1,3% (für 14,9 g Cr).

     

The study of complex equilibria of uranium(VI) with selenate

Uranyl (M)-selenate (L) complex equilibria in solution were investigated by spectrophotometry in visible range and potentiometry by means of uranyl ion selective electrode. The formation ML and ML(2) species was proved and the corresponding stability constants calculated were: log beta(1) = 1.57(6) +/- 0.01(6), log beta(2) = 2.42(3) +/- 0.01(3) (I = 3.0 mol 1(-1) Na(ClO(4), SeO(4)) (spectrophotometry) at 298.2 K. Using potentiometry the values for infinite dilution (I --> 0 mol 1(-1)) were: log beta(1) = 2.64 +/- 0.01, log beta(2) 3.4 at 298.2 K. Absorption spectra of the complexes were calculated and analysed by deconvolution technique. Derivative spectrophotometry for the chemical model determination has also been successfully applied.     

Synergistic extraction of uranium(VI) with 1-phenyl-3-methyl-4-acylpyrazolone-5 and neutral extractants

The synergistic extraction of uranium(VI) from hydrochloric acid solution with five chelating agents: 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (PMBP), 1-phenyl-3-methyl-4-acetylpyrazolone-5 (PMAP), 1-phenyl-3-methyl-4-(2-chlorobenzoyl)pyrazolone-5 (PMCBP), 1-phenyl-3-methyl-4-(p-nitrobenzoyl)pyrazolone-5 (PMNBP) and 1-phenyl-3-methyl-4-trifluoroacetylpyrazolone-5 (PMTFP) plus the neutral extractants tributylphosphate (TBP), dioctyl sulfoxide (DOSO) and trioctylphosphine oxide (TOPO) in chloroform has been investigated. The extraction coefficients have been found to be greater for such mixtures than the individual component. The formulas of the extracted species have been determined to be UO₂A₂B (where HA = chelating agent, B = neutral extractant). Extraction power of these chelating agents increases as follows: PMCBP>PMNBP>PMTFP=PMBP>PMAP. Synergistic extraction power of the neutral extractants increases as follows: TOPO>DOSO>TBP. The extraction equilibrium constants have been calculated. The mechanism of the synergistic extraction and possible structure of the extracted species are discussed.     

Spectrophotometric determination of uranium(VI) with 3-thianaphthenoyltrifluoroacetone

Summary Two visible spectrophotometric methods are described for the determination of uranium(VI) with 3-thianaphthenoyltrifluoroacetone at aph of 6.0. The effect due toph, time, solvents, reagent concentration and diverse ions are reported. Beer's law is obeyed in both cases and the molar extinction coefficients at 408 and 446 nm are 1.7·10⁴ and 2.3·10³ respectively.

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Zusammenfassung Zwei spektrophotometrische Methoden zur Bestimmung von U(VI) mit 3-Thianaphthenoyltrifluoraceton bei ph 6,0 wurden beschrieben. Der Einfluß vonph, Zeit, Lösungsmitteln, Reagenskonzentration und verschiedenen Fremdionen wurde angegeben. Das Beersche Gesetz wird in beiden Fällen befolgt. Der molare Extinktionskoeffizient bei 408 bzw. 446 nm beträgt 1,7 · 10⁴ bzw. 2,9 · 10³.

     

Investigation of the interaction between 1-hydroxyethane-1,1'-diphosphonic acid (HEDP) and uranium(VI)

A detailed study, using a panel of spectroscopic analytical methods, of the complexation between 1-hydroxyethane-1,1'-diphosphonic acid (HEDP) and uranyl ion (UO(2)(2+)) is reported. Results suggest that the metal complex is present as only 1:1 (metal/ligand) species at low concentration (<10(-)(4) M). The conditional constants of this complex were determined at various pH using time-resolved laser-induced fluorescence (TRLIF) and electrospray ionization mass spectrometry (ESI-MS). Further investigations indicate the presence of a 1:2 (metal/ligand) complex at higher concentrations ( approximately 10(-)(2) M). Selectivity studies as well as structural aspects are presented.     

Thermal decomposition of 1,2-dimethyl-3(5)-(4-R-styryl)-pyrazolium iodides

The reaction of 1,2,3(5)-trimethylpyrazolium iodide with aromatic aldehydes yielded the series of 1,2-dimethyl-3(5)-(4-R-styryl)pyrazolium iodides (R = H, NMe₂, NO₂). The quantitative ratio of 1-methyl-3- and -5-(4-R-styryl)pyrazoles formed in the thermal decomposition of the above-mentioned pyrazolium iodides depends on steric factors in the initial compounds and on the electronic influence of the substituent R. A simple method was proposed for the production of trans,trans-1,4-bis(1-methyl-3-pyrazolylvinyl)benzene and 1-methyl-3,5-distyrylpyrazole, which possess fluorescent properties.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1533–1536, November, 1984.     

Experimental and density functional studies on two structurally similar antipyrine derivatives: 4-(2-hydroxy-5-nitrobenzylidene-amino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one

The Schiff base compounds, 4-(2-hydroxy-5-nitr- obenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpy- razol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenz- ylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one, have been synthesized and characterized by elemental analysis, IR, and X-ray single crystal determination. Density functional calculations of the structures, natural bond orbitals, and frontier molecular orbitals and Mülliken charge analysis on the compounds were performed at B3LYP/6-31+G(d) level of theory. Vibrational frequencies were also predicted, assigned, and compared with the experimental values, which supported each other.     

2,2’-(4-氯苯基)亚甲基双(3-羟基-5,5-二甲基-2-环己烯-1酮)的晶体结构

标题化合物C23H27O4Cl是由邻氯苯甲醛与5，5-二甲基-1，3-环己二酮在N，N-二甲基甲酰胺中反应而得。结构通过单晶X-射线衍射法测定，其晶体属于单斜晶系，空间群晶体结构用直接法解出，使用全矩阵最小二乘法对原子参数进行修正，最后的偏离因子为在晶体结构中，存在两个共轭的烯醇式结构。四个C－O健长分别为1．283（2），1．285（2），1．287（3）和1．298（2）