Time-Dependent Molecular Rearrangement Of [Au(N-9-Adeninate)(Pta)] In Aqueous Solution And Aggregation-Induced Emission In A Hydrogel Matrix

An in-depth study of the molecular rearrangement of the complex [Au(N-9-adeninate)(PTA)] (1), promoted in aqueous solution, is presented. This complex, which has been previously described as forming dimers in its crystalline form, is also demonstrated as being able to assemble into an infinite Au-I center dot center dot center dot Au-I chain polymer. The structural motifs are tentatively related to the dramatic modification of the photoemissive properties of 1 in water solution at long times, with the aid of UV-vis and photoluminescence measurements, PGSE-NMR, and theoretical calculations. A subtle equilibrium in favor of aurophilically governed aggregates has been envisaged as the driving force of the molecular rearrangement. Furthermore, 1 has been explored as an additive of the hydrogel of [Au(N-9-adeninate)(PMe3)] (2) for a further tuning of its photophysical properties without loss of the gel texture.