Synthesis, crystal structure, photoluminescence and photochemistry of bis(triphenylphosphine)silver(I) flavonolate

The complex Ag(I)(flavonolate)(PPh3)2 has been prepared and characterized including the crystal structure. This compound shows in degassed solution two emission bands, a fluorescence at λ max=505 nm and a phosphorescence at λ max=780 nm. Both emissions originate from lowest-energy flavonolate intraligand excited singlet and triplet states, respectively. In the presence of oxygen, the phosphorescence disappears and the complex becomes light-sensitive. The flavonolate ligand undergoes a photooxidation by oxygen.