Synthesis, Characterization, Electrochemical and Spectroelectrochemical Properties of Ruthenium(Ⅱ) Complexes Containing Phenylcyanamide Ligands and Effect of the Inner- Sphere on the Ru-NCN Chromophore

摘要

[Ru(terpy)(bpy)(L)]PF_6 complexes, where terpy is 2,2′:6′,2″- terpyridine, bpy is 2,2′ - bipyridine and L is monoanions of 4 - bromophenylcyanamide (4 - Brpcyd), 4-methoxyphenylcyanamide (4 - MeOPcyd), 2, 4 - dibromophenylcyanamide (2,4 - Br_2pcyd), 2,4-dimethylphenylcyanamide (2,4 - Me_2pcyd), 2 - methylphenylcyanamide (2 - MePcyd), phenylcyanamide (Pcyd) and naphtylcyanamide (ncyd) have been prepared and characterized by elemental analysis, IR, ~1H-NMR and UV-vis spectroscopies and cyclic voltammetry. Spectroelectrochemistry was used to generate the electronic absorption spectra of the Ru(Ⅲ) complexes, [Ru(terpy)(bpy)(L)]~(2+) in acetonitrile solution. The spectral data associated with the Ru(Ⅲ)-cyanamido LMCT chromophore were compared to those derived from Ru(Ⅲ) analogues in order to gain a greater understanding the effect of spectator ligands on the nature of the Ru(Ⅲ)-Cyanamide bond. The data supports greater covalency in the Ru(Ⅲ)-cyanamide bond of [Ru(terpy)(bpy)(L)]~(2+) complexes compared to their Ru(Ⅲ) analogues.