Molecular structure copper diketonates

Sirio, C Poncelet, O., Hubert-Pfaizgraf, L. G., Daran, J. C., and Vaissermann, J., Reactions between copper p-diketonates and metal alkoxides as a route to soluble and volatile copper(II) oxide precursors Synthesis and molecular structure of Cu4( J-3,n -0C2H40iPr)4(acac)4 and (acac)Cu(p-OSiMe3)2Al(OSiMe3)2, Polyhedron, 11, 177 (1992). 

More advanced semiempirical molecular orbital methods have also been used in this respect in modeling, e.g., the structure of a diphosphonium extractant in the gas phase, and then the percentage extraction of zinc ion-pair complexes was correlated with the calculated energy of association of the ion pairs [29]. Semiempirical SCF calculations, used to study structure, conformational changes and hydration of hydroxyoximes as extractants of copper, appeared helpful in interpreting their interfacial activity and the rate of extraction [30]. Similar (PM3, ZINDO) methods were also used to model the structure of some commercial extractants (pyridine dicarboxylates, pyridyloctanoates, jS-diketones, hydroxyoximes), as well as the effects of their hydration and association with modifiers (alcohols, )S-diketones) on their thermodynamic and interfacial activity [31 33]. In addition, the structure of copper complexes with these extractants was calculated [32]. 

In the meantime, Ohta et studied the complete series of symmetric copper complexes ((53) M = Cu R = R = C H2 +i, = 0 to 14), which confirmed the previous results. The ligand showed a crystal smectic E phase from the octyl derivative onwards as determined by miscibility studies. The first four complexes ((53) M = Cu R = R = C H2 +i, = 0 to 3) were not mesomorphic, then a mono tropic phase was detected for = 4, which became enantiotropic for > 5. Moreover, for n = l and 8, the copper complexes showed an additional mesophase, while the nonyl derivative exhibited two additional mesophases. Crystalline structures of some tetra-alkyl copper, palladium, and nickel complexes of / -diketonates revealed that the flat molecular species were stacked into columns, the planes of the molecules forming a small tilt with respect to the columnar axis-these columns were further organized into layers. Variable-temperature and NMR ... 

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