P-Diketones structure

Batzar, K. Goldberg, D.E. Newman, L.J. Effect of P-diketone structure on the synergistic extraction of uranyl ion by tributylphosphate, J. Inorg. Nucl. Chem. 29 (1967) 1511-1518. 

An enolic OH derived from the P-diketone structural unit can act as the nucleophile in a nucleophilic acyl substitution to give a six-membered oxygen heterocycle known as a pyrone. 

Self-Assembled Metallo-Supramolecular Systems Incorporating P-Diketone Motifs as Structural Elements David J. Bray, Jack K. Clegg, Leonard F. Lindoy and David Schilter... 

The bifluoride ion, HFj 297 Strong hydrogen bonding in p-diketones 309 Keto/enol equilibrium 310 Structures 312 Hydrogen-bond energies 314 Vibrational modes 315 Nmr spectroscopy 317... 

The vibrational assignments for a selection of P-diketones are given in Table 10, which includes those p-diketones for which complete structural and nmr data are available. 

Purpurogallin (5), a red-brown to black mordant dye, forms from electrolytic and other mild oxidations of pyrogallol (1). The reaction is believed to proceed through 3-hydroxy-o-benzoquinone (2) and 3-hydroxy-6-(3,4,5-ttihydroxyphenyl)-o-benzoquinone (3). The last, in the form of its tautomeric triketonic structure, represents the vinylogue of a p-diketone. Acid hydrolysis leads to the formation of (4), followed by cyclization and loss of formic acid... 

The products of partial substitution for the OR-groups, i.e., alkoxocarbox-ylates, P-diketonates M(OR)mX , where X= RCOO, acac, thd, etc.—the mixed-ligand complexes—usually are more soluble and stable than M(OR) , as their molecules contain the chelate cycles. Mehrotra et al. [223] have described a great number of such products (usually liquid or amorphous), in which individuality appeared sometimes questionable. During recent years, however, in connection with the application of these compounds to the synthesis of oxides, interest in them has increased, and a number of them have been isolated and structurally characterized (Chapter 7). Unfortunately, length restriction did not permit us to present a complete review of their chemistry in this book. 

A recent review [440], published 100 years after Werner s coordination theory was first presented, was dedicated to the complex compounds obtained on the basis of polypyrazolyl-borates or scorpionates. Complexes of this kind, an example of which is presented by structure 234, have been obtained with practically all p, /-elements and they can be examined as N-containing analogoues (MN4 coordination unit) of p-diketonates 2 (M04 coordination unit) ... 

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