Exploring Three Avenues: Chemo- and Regioselective Transformations of 1,2,4-Triketone Analogs into Pyrazoles and Pyridazinones.

A convenient approach to substituted pyrazoles and pyridazinones based on 1,2,4-triketones is presented. Chemo- and regiocontrol in condensations of t-Bu, Ph-, 2-thienyl-, and CO2Et-substituted 1,2,4-triketone analogs with hydrazines are described. The direction of preferential nucleophilic attack was shown to be switched depending on the substituent nature in triketone as well as the reaction conditions. The acid and temperature effects on the selectivity of condensations were revealed. Regiochemistry of heterocyclic core formation was confirmed by NMR and XRD studies. The facile construction of heterocyclic motifs bearing acetyl and (or) carbethoxy groups suggests them as promising mono- or bifunctional building blocks for subsequent transformations.

Perfluoroalkyl Chain Length Effect on Crystal Packing and [LnO8] Coordination Geometry in Lanthanide-Lithium ß-Diketonates: Luminescence and Single-Ion Magnet Behavior.

Functionalized perfluoroalkyl lithium ß-diketonates (LiL) react with lanthanide(III) salts (Ln = Eu, Gd, Tb, Dy) in methanol to give heterobimetallic Ln-Li complexes of general formula [(LnL3)(LiL)(MeOH)]. The length of fluoroalkyl substituent in ligand was found to affect the crystal packing of complexes. Photoluminescent and magnetic properties of heterobimetallic ß-diketonates in the solid state are reported. The effect of the geometry of the [LnO8] coordination environment of heterometallic ß-diketonates on the luminescent properties (quantum yields, phosphorescence lifetimes for Eu, Tb, Dy complexes) and single-ion magnet behavior (Ueff for Dy complexes) is revealed.

Heterometallic Molecular Architectures Based on Fluorinated ß-Diketone Ligands.

This review summarizes the data on the synthesis of coordination compounds containing two or more different metal ions based on fluorinated ß-diketonates. Heterometallic systems are of high interest in terms of their potential use in catalysis, medicine and diagnostics, as well as in the development of effective sensor devices and functional materials. Having a rich history in coordination chemistry, fluorinated ß-diketones are well-known ligands generating a wide variety of heterometallic complexes. In this context, we focused on both the synthetic approaches to ß-dicarbonyl ligands with additional coordination centers and their possible transformations in complexation reactions. The review describes bi- and polynuclear structures in which ß-diketones are the key building blocks in the formation of a heterometallic framework, including the examples of both homo- and heteroleptic complexes.