Heterometallic Au(I)-Cu(I) Clusters: Luminescence Studies and O-1(2) Production

Theuse of heterometallic Au/Cu systems containing a largenumber of metallophilic contacts is an ideal platform for obtainingred phosphorescent materials. The compounds synthesized in this workpresent an ionic character due to the reaction of gold-(I) complexeswith several copper-(I) salts. The counterion affects, in some cases,tuning the emission wavelength. All of the compounds have been testedas photosensitizers in the generation of singlet oxygen. Two different organometallic gold-(I) compounds containingnaphthaleneand phenanthrene as fluorophores and 2-pyridyldiphenylphosphane asthe ancillary ligand were synthesized (compounds 1 with naphthaleneand 2 with phenanthrene). They were reacted with three different copper-(I)salts with different counterions (PF6 (-), OTf-, and BF4 (-);OTf = triflate) to obtain six Au-(I)/Cu-(I) heterometallic clusters(compounds 1a-c for naphthalene derivativesand 2a-c for phenanthrene derivatives).The heterometallic compounds present red pure room-temperature phosphorescencein both solution, the solid state, and air-equilibrated samples, asa difference with the dual emission recorded for the gold-(I) precursors 1 and 2. The presence of Au-(I)-Cu-(I) metallophiliccontacts has been identified using single-crystal X-ray diffractionstructure resolution of two of the compounds, which play a directrole in the resulting red-shifted emission with respect to the gold-(I)homometallic precursors. Polystyrene (PS) and poly-(methyl methacrylate)(PMMA) polymeric matrices were doped with our luminescent compounds,and the resulting changes in their emissive properties were analyzedand compared with those previously recorded in the solution and thesolid state. All complexes were tested to analyze their ability toproduce O-1(2) and present very good values of phi(Delta) up to 50%.