Emission and Photochemical Reactivity in Fluorescent Arene Complexes of Cyclopentadienylruthenium(II). Requirements for an Emissive CpRu(arene)+ Complex

The syntheses and characterization of five new compounds that contain the CpRu + (Cp=η 5 -C 5 H 5 ) moiety bound to a highly fluorescent arene ligand are reported. Nonemissive complexes of the highly emissive laser dyes coumarin-7 (3-(2'-Benzimidazolyl)-7-(N,N-diethylamino) coumarin) and coumarin-30 (3-(2'-N-methylbenzimidazolyl)-7-(N,N-diethylamino)coumarin) in which the CpRu + group binds the dye benzimidazolyl arene ring were prepared and are compared to the structurally analogous, emissive complex of coumarin-6