Résumé
We report the synthesis and characterization of carbazole–ruthenium complexes linked by an acetylene spacer. We characterized the ground state electronic properties of these complexes by cyclic voltammetry and absorption spectra. The excited state behavior was investigated after pumping the carbazole moiety. The presence of the attached ruthenium with its oxidation state Ru
2+ suppressed strongly the fluorescence of the carbazole in both pentaammine [Ru
2+(NH
3)
5L] and terpyridine bipyridine [Ru
2+(tpy)(bpy)L] (tpy=2,2′:6′,2′′-terpyridine, bpy=2,2′-bipyridine) ruthenium compounds. In the case of Ru(NH
3)
5L, both Ru
2+ and Ru
3+ compounds (the latter obtained by chemical or electrochemical oxidation) showed a decrease of the fluorescence of the carbazole generally observed for other pentaammine complexes. The ligand (L=3-(2-(4-pyridyl)-ethylenyl)-carbazole) has been studied and showed delocalization of an electron between the triple bond spacer and the chromophore. It also showed solvent dependence in the excited state.