Blue and orange oxygen responsive emissions in the solid state based on copper(I) complexes bearing dodecafluorinated diphosphine and 1,10-phenanthroline derivative ligands

Reversible oxygen sensing abilities based on blue and orange photoluminescence in the solid state are achieved by using newly synthesized copper(I) complexes bearing diimine and dodecafluorinated di-phosphine ligands. We found that the blue emission of [Cu(dmp)(dfppe)]PF6 (dmp = 2,9-dimethyl-1,10-phenanthroline, dfppe = 1,2-bis[bis(pentafluorophenyl) phosphino] ethane) in the solid state is very strong under argon, while it is nearly invisible under air. Single crystal X-ray structural analysis reveals that the complex has significant columnar void spaces. [Cu(dmp)(dfppe)] PF6 shows an extremely long lifetime of the emission in the solid state under an argon atmosphere (tau(1) = 160 mu s (88%), tau(2) = 22 mu s (12%)), which is one of the largest values for all copper(I) complexes bearing diimine ligands, and it is drastically decreased under air (tau(1) = 2.4 mu s (85%), tau(2) = 0.5 mu s (15%)). The employment of the dfppe ligand markedly increases the contribution of ligand centred transition, leading to the long-lived excited state. The orange oxygen responsive emission of [Cu(47dmp)(dfppe)]PF6 (47dmp = 4,7-dimethyl-1,10-phenanthroline) is also examined with the help of an investigation of the photophysics of five new compounds of the copper(I) complexes.