Neutral ruthenium(II) complexes of phenylcyanamido ligands

Neutral Ru(II) complexes with the formula trans-[Ru(trpy*)(L2)(pcyd)] have been prepared, where trpy* = 4,4′,4″-tri-tert-butyl-terpyridine, L2 = 2-pyrazinecarboxylato (pca), 2-pyridinecarboxylato (pic), acetylacetonato (acac) and pcyd = 3-chlorophenylcyanamido (3-Clpcyd), 2,3-dichlorophenylcyanamido (2,3-Cl2pcyd), 2,4,6-trichlorophenylcyanamido (2,4,6- Cl3pcyd), 2,3,4,5-tetrachlorophenylcyanamido (2,3,4,5-Cl4pcyd) and 3,4,5-trimethoxyphenylcyanamido (3,4,5-(OMe)3pcyd). Spectroelectrochemistry was performed on these Ru(II) complexes to obtain the visible absorption spectrum of the Ru(III)–cyanamide ligand-to-metal charge transfer chromophore. The Ru(III)–cyanamide metal–ligand coupling elements of these complexes were compared to other Ru(III)–cyanamide complexes.