Mn(II), Co(II), Ni(II) and Cu(II) chelates with3-phenyl-4-(p-methoxyphenylazo)-5-pyrazolone have been synthesized and were characterized by elemental and thermal analyses as well as
by IR, UV-VIS, 1HNMR, conductometric and magnetic measurements. The first stage in the thermal decomposition process of these complexes shows
the presence of water of hydration, the second denotes the removal of the coordinated water molecules. The final decomposition
products were found to be the respective metal oxides. The data of the investigated complexes suggest octahedral geometry
with respect to Co(II) 1:1, tetrahedral for Ni(II) 1:1and 2:3; square planar for Cu(II) 1:1 and 2:3; the complexes with no
coordinated water molecules (2:3) Co(II) and Mn(II) complexes are tetrahedral.
A series of novel chelating reagents 1-phenyl-3-Methyl-4-p-Nitro-Benzoyl-Pyrazolone-5 /PMNBP/, 1-Phenyl-3-Methyl-4-o-Chlor-Benzoyl-Pyrazolone-5 /PMCBP/, 1-Phenyl-3-Methyl-4-Acyl-Pyrazolone-5 /PMAP/ have been synthesized. The extraction of U/VI/ and U/IV/ from hydrochloric acid in chloroform with these reagents as well as 1-Phenyl-3-Methyl-4-Benzoyl-Pyrazolone-5 /PMBP/ has been studied. The influence of the concentration of the reagents in organic phase, on the distrubtion ratio /D/, has been measured. The coordination of the compounds has been determined with the slope method, and the equilibrium constants kex, were measured.
Authors:P. K. Mohapatra, P. B. Ruikar, and V. K. Manchanda
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 DPu value was influenced marginally. The effect of a redox reagent on Pu extraction was also investigated.
Authors:R. Cierpiszewski, D. Rusińska-Roszak, J. Szymanowski, W. Mickler, and E. Uhlemann
The rate of copper extraction with individual 4-acyl-5-pyrazolones and the stability of various enolic and keto forms and
their monohydrates were studied. The rate of extraction depends mainly upon the structure of substituent at position 4 and
falls when the substituent becomes spacy. The effect of the substituent at position 1 is rather low. The enolic form with
intramolecular hydrogen bonding is the most stable. It can form hydrates with water molecules without intramolecular hydrogen
The extraction of group VIII elements with 1-phenyl-3-methyl-4-trifluoracetyl-pyrazolone-5 from aqueous solutions in chloroform
has been studied as a function of pH. Fe(III), Ni(II), Pd(II) and Rh(III) show partial extraction whereas Co(II) is extracted
quantitatively. The effect of citrate, cyanide, fluoride, iodide, thiosulphate and thiourea on the extraction of metal ions
has been investigated. Back-extraction studies were carried out to strip metal ions from organic phase into appropriate aqueous
solutions. Based on these findings some useful analytical separations have been proposed and a few of their possible applications
have been discussed.
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
Authors:S. Abdel-Latif, O. El-Roudi, and M. Mohamed
Infrared (IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TG), derivative thermogravimetric analysis (DTG),
differential thermal analysis (DTA) and molar conductivity studies have been carried out on the chelates of Mn(II), Co(II),
Ni(II), Cu(II) and Zn(II) with 3-methyl- and 3-phenyl-4-nitroso-5-pyrazolones. The solid chelates were synthesized, separated,
analyzed and their structures were elucidated. The data obtained show that almost all of the prepared chelates contain water
molecules in their coordination sphere. The initial stage in the thermal decomposition process of these chelates shows the
presence of water molecule, the second denotes to the intermediate products. The final decomposition products were found to
be the respective metal oxides. The NMR spectrum of 3-methyl-4-nitroso-5-pyrazolone ligand shows the existence of the oxime
rather than the nitroso form. 3-phenyl-4-nitroso-5-pyrazolone acts as a neutral bidentate ligand whereas 3-methyl-4-nitroso-5-pyrazolone
acts as monobasic bidentate ligand bonded to the metal ions through the two oxygen atoms of the carbonyl and nitroso groups.
The solid chelates prepared behave as non-electrolytes in DMF solution. The coordination numbers of the obtained chelates
using 3-methyl-4-nitroso-5-pyrazolone are four on applying the mole ratio 1:1 and six on using 1:2 mole ratio. In case of
using the ligand 3-phenyl-4-nitroso-5-pyrazolone the coordination number is six in both cases.
A study of the synergistic extraction of uranium(VI) from sulphuric acid solution with 1-phenyl-3-methyl-4-(2-chlorobenzoyl)-pyrazolone-5 (PMCBP) together with di-(2-ethylhexyl)-phosphoric acid (HDEHP) and also mono-(2-ethylhexyl)-2-ethylhexyl-phosphate (HEHEHP) is described. The results suggest that the compositions of the extracted species is UO2XHA2 and UO2X2H2A2 respectively. Models for the extraction mechanism is also discussed.
The extraction of group IB, IIB and IIA-VA elements with 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 in chloroform has
been investigated as a function of pH. The stripping of metal ions into solutions of KCN, HClO4 and appropriate pH buffers has been studied. The masking effects of cyanide, citrate, iodide, thiosulphate and thiourea on
the extraction have been examined. Selective group and individual separations have been proposed on the basis of pH control,
masking effects and back-extraction.
Authors:F. Zantuti, S. Ivanova, Yu. Novikov, and B. Myasoedov
Conditions for neptunium recovery from nitrate solution containing large amounts of uranium by extraction with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (PMBP), and a mixture of PMBP with di-2-ethyl-hexylphosphoric acid (HDEHP) were studied. A two-stage technique, based on removal of uranium macroamounts at the first stage by means of extraction of uranium with PMBP and HDEHP mixture, and neptunium extraction by PMBP at the second stage, was suggested.