L-phenyl-3-methyl-4-acyl-5-pyrazolones

Figure 2.5 Molecular structures of l-phenyl-3-methyl-4-acyl-5-pyrazolones.

A limitation of jS-diketone extractants like TTA is the relatively low acidity of the extractant which requires that the aqueous pH be adjusted to above 4 for efficient extraction of the trivalent actinides and lanthanides. A class of extractants having a similar structure but greater acidity are the l-phenyl-3-methyl-4-acyl-5-pyrazolones,... 

Skytte Jenseni has studied the possibility of using substituted l-phenyl-3-methyl-4-acyl-pyrazolones-5 as extractants for a number of elements Including uranium (Vl), thorium, and lanthanum. The pH for 505 extraction of trace amounts of these elements by a IM solution of chelating agent in chloroform Is given In Table XXXII. The PH q for TTA is given for con arlson. ... 

Electron-poor and electron-rich 4-acyl substituted pyrazolones (Hap) react with NaOH and M(N03)3 (M = Eu, Gd) to afford [M(ap)3(OH2)2]" - The analogous [Tb(ap)3 (OPPhs)] (Hap = l-phenyl-3-methyl-4-(2-ethylbutyryl)-5-pyrazolone) shows high electro-luminiscence performance" . 

Bacher, W. Keller, C. 4-Acyl-substituierte l-phenyl-3-methyl-pyrazolone-5 als chelat-bildner ftir actinidenionen, J. Inorg. Nucl. Chem. 35 (1973) 2945-2956. 

The next category of f)-diketones are 4-acyl-l-phenyl-3-methyl-5-pyrazolones (see Eigure 2.5) and their analogs of 3-phenyl-4-acyl-5-isoxazolones (see Eigure 2.6). The latter type of P-diketones have stronger acidities (lower pA a values) than the former, and have recently been smdied as promising light conversion molecular devices [46-51]. 

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