Water-induced red luminescence in ionic square-planar cyclometalated platinum(II) complexes

This work describes the synthesis and characterization of a series of water soluble Pt(II) complexes, with different degree of hydrophobicity, and thanks to d(8)-d(8) metal-metal and/or pi-pi interactions, these complexes are able to aggregate in aqueous solutions. Aggregates are luminescent more efficiently than the single molecule, exhibiting one of the highest emission quantum yield reported up to date for Pt(II) complexes dissolved in aerated water solution at room temperature (1*10(5) M). Moreover, differently from single molecule, aggregates luminescence is not quenched by molecular oxygen.