From mono to polydentate azole and benzazole derivatives, versatile ligands for main group and transition metal atoms

Herein we discuss contributions in the coordination chemistry of azoles and benzazoles, from our and some other research groups. Reactions of polydentate ligands with a diverse combination of donor atoms, as N, O, S, R with main group and transition metals are commented, as well as their structural analysis. There is a versatile chemistry involved in these compounds, based on a great structural diversity. The ligands promote hypervalent atoms, a wide spectrum of molecular geometries and interactions. The central atoms vary from tri- to octacoordinated. Metallacycles are formed with the participation of the metal ion into the electronic delocalization of the organic pi-systems. The high electron density of the ligands, their planar delocalized and rigid framework favor many weak interactions, giving place to macromolecular assemblies based on hydrogen bonds, pi-stacking and Lewis acid-base coordination. The compounds offer the possibility of their use as antiparasites drugs, biocides or anticancer substances and in materials science. (C) 2009 Elsevier B.V. All rights reserved.