The evolution of β-diketone or β-diketophenol ligands and related complexes

The design and properties of the most relevant and illustrative examples of beta-diketones or beta-ketophenols and related complexes, together with their evolution into more sophisticated linear or tridimensional polymeric systems, are reviewed. The introduction of different functionalities at the periphery of the coordinating moiety of beta-diketones and the physico-chemical properties arising from the related complexes are considered also in correlation with their potential in the preparation of probes and devices, where molecular components are essential. The role of the different metal ions in directing the preparation pathways and tuning peculiar properties to the resulting systems is discussed. The synthetic procedures aimed at introducing a progressively increasing number of carbonyl groups inside the coordination moiety or at further inserting phenol groups at the end of or between the polyketone moiety and the formation of the related homo- and heteropolynuclear complexes are reported together with the stereochemical. magnetic and optical properties arising from these aggregations. The ability of poly-beta-diketones in the selective separation of specific metal ions across liquid membranes is also evaluated. Furthermore, the development of the resulting complexes into the third direction, via coordination of appropriate bridging groups, with the formation of discrete or polymeric systems is illustrated in detail. Finally, the insertion of additional donor groups at the periphery or between the beta-diketonato moieties was taken into consideration, together with the role of specific spacers with or without additional donors in determining peculiar architectures and properties of the resulting complexes. (C) 2008 Published by Elsevier B.V.