Au(I) supramolecular structures used in molecular recognition processes.

Abstract

In the latest years there has been an increasing interest in the study of certain organometallic gold (I) complexes, due to the great variety of supramolecular structures that they form. Through the establishment of intramolecular weak interactions a process of self-assembly occurs; structures such as fibres, micelles and vesicles have been reported and some have proven to be gelators. A wide range of applications have been envisioned for these complexes in several fields: medicine, materials chemistry, applications in detectors, light harvesting and catalysis. In the work presented herein, the study of two families of organometallic gold (I) complexes is presented. The first family are neutral complexes with general formula [[Au(4-ethynylbipyridine)(L)], and the second are charged complexes with general formula [Au(N-methyl-4-ethynylpyridine)(L)]X, where X=iodide, triflate and perchlorate. The ligands L are phosphines DAPTA and PTA. The purpose of this work is to study several properties of these complexes to better understand their nature. The aggregation process (or self-assembly) over time, as a function of concentration and the solvent will be studied for the first neutral complexes. In addition, molecular recognition studies with three lanthanide cations will be performed. The synthesis and later characterization of complexes [Au(N-methyl-4-ethynylpyridine)(L)]X with X=iodide and triflate will be carried out. Several unsuccessful attempts to synthetize the complex with X=perchlorate will be described in detail. Finally, aggregation studies have been carried out: their solvatochromism has been studied and their supramolecular structures have been observed through optical microscopy.