Anionic lanthanide complexes with 3-methyl-4-formyl-1-phenyl-5-pyrazolone

The coordination compounds Na[LnL₄] · 2H₂O and [NBu₄][LnL₄] (Ln = Nd, Sm, Eu, Tb; HL is 3-methyl-4-formyl-1-phenyl-5-pyrazolone) have been synthesized and studied by IR spectroscopy and thermogravimetry. According to X-ray diffraction data, the coordination polyhedra of lanthanides are shaped as square antiprisms and formed by the oxygen atoms of four deprotonated moieties of the enol form of 4-formyl-5-pyrazolone. In the complex Na[EuL₄] · 2H₂O, sodium cations are bonded to the two nitrogen atoms of pyrazole heterocycles, combining discrete complex anions into two interpenetrating three-dimensional frameworks. Polycrystalline samples of neodymium(III), samarium(III), and terbium(III) complexes manifest intense luminescence in the spectral regions that are typical for them.     

The solid-state michael addition of 3-methyl-1-phenyl-5-pyrazolone

A novel solid-state Michael addition between pyrazolone 1 and 4-arylidenepyrazolones 2 at ambient temperature produced Michael adducts, 4,4′-arylidenebis(3-methyl-1-phenyl-5-pyrazolones) 3. Pyrazolones 3 formed salts 4 with Cu²⁺ in solution, indicating the enolic structure of the pyrazolone rings. The reactivity of 2 with 1 is discussed in terms of the electronic and steric effects of the substituent on the arylidene group of compounds 2 . Pyrazolone 1 also underwent the solid state Michael addition reaction with maleimide at 100° to give the adducts 7,8 and 9 .     

Recovery of plutonium from oxalate supernatant using 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

Summary Extraction of Pu(IV) from oxalate supernatant was carried out employing 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) in xylene as extractant. The conditions for quantitative extraction were determined by the variation of ligand, oxalic acid and nitric acid concentration. Quantitative stripping was achieved using a mixture of 0.4M oxalic acid and 0.4M ammonium oxalate. Extraction of Pu(IV) from synthetic oxalate supernatant solution containing 3M nitric acid and 0.2M oxalic acid was investigated under various loading conditions employing 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone in xylene as extractant. Under uranium loading conditions the Pu extraction decreased significantly while with increased Pu loading whereas the D_Pu value was influenced marginally. The effect of a redox reagent on Pu extraction was also investigated.     

Preconcentration of indium with 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone on silica gel

Indium was quantitatively retained at pH > 2.8, and could be removed by treatment with 1 M hydrochloric acid. The adsorption capacity of the material was 32 μmol In g^?1. Nickel, cobalt and zinc had no effect on the retention of indium.     

Thermal and spectroscopic studies of scandium complex of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

The scandium complexes of Sc(PMBP)₃·H₂O (non-crystal) and Sc(PMBP)₃ (crystal) with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) were prepared and characterized by thermal analysis, IR, NMR and MS spectroscopies. The crystal structure of the complex, obtained by X-ray analysis, indicates that PMBP is a bidentate ligand in the complex and that the Sc atom is six-coordinate and is in a meridional octahedral environment. The order of the ring current effect on the pyrazolone ring is Sc(PMBP)₃ >PMBP(enol)> PMBP(keto).

The metal to ligand stoichiometry was found to be 1:3. The crystalline complex melts at 209 °C, followed by degradation at about 310 °C, with the beginning of decomposition. The enthalpy of melting was found to be 61 kJ/mol. On the other hand, the non-crystalline complex was found to change into a crystalline complex at 176 °C with an exothermic reaction before melting at 217 °C. The IR band observed at approximately, 450 cm⁻¹ is possibly due to the stretching of the Sc–O bond.     

C-alkylation of 3-methyl-1-phenyl-5-pyrazolone by hexafluoroacetone and its imines

Conclusions Regiospecificity was demonstrated for C-alkylation in the reactions of 3-methyl-1-phenyl-5-pyrazolone with hexafluoroacetone and the trifluoroacetylimine and benzenesulfonylimine of hexafluoroacetone at C⁴ of the heterocycle.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 684–686, March, 1987.     

Mixed ligand chelate extraction of lanthanides with 1-phenyl-3-methyl-4-octanoyl-5-pyrazolone systems

The equilibrium extraction behavior for a series of representative trivalent lanthanide ions, Pr, Eu, and Yb, using chloroform solutions containing 1-phenyl-3-methyl-4-octanoyl-5-pyrazolone (HPMOP), either alone or combined with 1,10-phenanthroline (phen), trioctylphosphine oxide (TOPO) or methyltrioctylaromonium chloride (R₃R'NCl), is studied. The results demonstrate that these lanthanides are extracted as LnP₃, or in the presence of phen or TOPO. as LnP₃ · phen or LnP₃ · TOPO, or in the presence of R₃R'NCl, as R₃R'NLnP₄. The effects of phen, TOPO, and R₃R—NCl on the extraction of lanthanide ions with HPMOP are more pronounced than their effects with 8-quinolinol or 5,7-dibromo-8-quinolinol.     

Crystal structure and photoisomerism of 1-phenyl-3-methyl-4-benzal-5-pyrazolone 4-butylthiosemicarbazone in solid state

The structure of 1-phenyl-3-methyl-4-benzal-5-pyrazolone 4-butylthiosemicarbazone (PMBP-BTSC) was confirmed by¹H NMR, IR, elemental analyses, and X-ray crystallographic analysis. The photoisomerization of PMBP-BTSC in solid state was studied in the condition of UV-Vis irradiation, and the mechanism of the photoisomerization was interpreted by double proton transfer. Moreover, the effect of the alkyl chain length in the side chain of a series of 4-acyl pyrazolone derivatives on the photochemical properties was discussed.     

Thermal decomposition of iron(III) complex of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

A pyrazolonate (PMBP) of iron(III) was prepared and its metal to ligand stoichiometry was shown to be 1∶3. The decomposition of the complex was studied by thermogravimetry and differential analyses under an air atmosphere. The complex undergos two endothermic reactions without loss in mass, at 160 and 218°C, followed by an exothermic reaction at 480°C involving decomposition of the ligands. Intermediates obtained by melting of the Fe-PMBP complex were characterized by X-ray diffraction analysis. The Fe-PMBP complex was confirmed by HPLC to be a mixture of two isomers.     

Equilibria and kinetics of the extraction of gallium with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

The equilibria and kinetics of the solvent extraction of gallium(III) from aqueous monochloroacetic acid [HA] media with a benzene solution of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone [PMBP or HL] has been studied at 25 ± 0.1° and an ionic strength of 0.2. The species extracted was found to be GaL₃. The value of the acid dissociation constant of PMBP determined spectrophotometrically was 1.17 × 10⁻⁴. The values of the partition coefficient of PMBP and the extraction constant of its gallium complex between an aqueous and a benzene phase were found to be 3.72 × 10³ and 2.51 × 10⁴, respectively. The rate of extraction was first-order with respect to the concentrations of gallium(III) in the aqueous phase and PMBP in the organic phase, inversely first- and second-order with respect to the hydrogen-ion concentration and zero- and first-order with respect to the concentration of monochloroacetate ions. Two mechanisms operate for this extraction, depending on the pH of the aqueous phase, one where the formation of the first complex, GaL²⁺, between Ga³⁺ and L⁻ in the region of pH < 1.6 becomes the rate-determining step, and the other where the formation of the first complex between GaA²⁺ and L⁻ in the region of pH 2.0–2.3 is the rate-determining step. The rate constant for the first of these reactions was calculated to be 1.62 × 10⁴l.mole⁻¹.sec⁻¹, but that for the second could not be determined.     

Studies on extraction of manganese(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone

The extraction of Mn(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone (HA) in MIBK has been studied. Mn(II) is extracted as MnA(2). The extraction constant for each 4-acyl compound was calculated. The effect of temperature on the extraction of Mn(II) has also been investigated.     

Studies on extraction of copper(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone

The extraction of Cu(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone (HA), in different organic solvents has been studied. The extraction mechanism of Cu(II) and the composition of the extracted species has been determined. Cu(II) was extracted as CuA₂, or in the presence of TOPO, as CuA₂TOPO. The extraction constants do not change regularly with increasing the length of acyl chain in the 1-phenyl-3-methyl-4-acyl-5-pyrazolone derivatives. The effect of the temperature on the extraction of Cu(II) has also been investigated.     

Capillary electrochromatography of 1-phenyl-3-methyl-5-pyrazolone derivatives of some mono-and disaccharides

Summary A packing procedure was adopted for capillary electrochromatography (CEC) that produces capillary columns with high separation efficiencies. The columns were fully packed, 50 cm long, with UV detection being performed through the packed section 30 cm from the inlet end. The CEC experiments were run at ambient pressure, with no additional pressure applied to the ends of the column. The stationary phase (octadecyl silica (ODS), 5 μm) promoted a high velocity electroosmotic flow (EOF), enabling rapid and efficient separation of a hydrocarbon test mixture. Some 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of mono- and disaccharides were baseline separated, using a 5 mM NaH₂PO₄ in 80% acetonitrile and 20% water (v/v) buffer solution. CEC shows promise for future applications in carbohydrate analysis. Presented at Balaton Symposium on High Performance Separation Methods, Siófok, Hungary, September 1–3, 1999     

Thermal decomposition of copper complexes of 1-phenyl-3-methyl-4-acyl-5-pyrazolone in air atmosphere

Copper complexes of some 1-phenyl-3-methyl-4-acyl-5-pyrazolones have been prepared. The complexes were characterized by elemental analyses and thermal analyses. It was shown that the melting points decrease linearly in increasing the molecular weight of the complexes.     

1-苯基-3-甲基-4-(4-羟基-3-甲氧基)-苯甲叉-吡唑啉酮的微波合成和晶体结构

标题化合物C18H16N2O3是由香草醛和1-苯基-3-甲基-吡唑啉酮用微波辐射反应得到,结构通过单晶X-射线衍射法确定,其晶体属单斜晶系,空间群P21/c,Mr = 308.33, a = 21.101(4), b = 7.984, c = 20.076 ? = 115.81(1)? V = 3044.8(8) ? Z = 8, Dc = 1.345 g/cm3, = 0.093 cm-1, F(000) = 1296, 最终的偏离因子为R = 0.0403, wR = 0.0780, 分子之间存在氢键,形成了网状结构。     

Crystal structure and photochromism of 1-phenyl-3-methyl-4-benzyl-5-one-pyrazole S-methyl thiosemicarbazone

A new organic photochromic compound containing pyrazolone-ring photochromic functional unit: 1-phenyl-3-methyl-4-benzyl-5-one pyrazole S-methyl thiosemicarbazone (PMBP-smtsc) was synthesized. The photochromic properties and photochemical kinetics of PMBP-smtsc have been studied by UV reflectance spectra under irradiation of 365 nm light. The crystal structure analyses of photocolored product show the photochromism is due to the photoisomerization from enol form to keto form through an intermolecular proton transfer.