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

[Ru(terpy)(bpy)(L)]PF6 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 - Br2pcyd), 2,4-dimethylphenylcyanamide (2,4 - Me2pcyd), 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.