Synthesis, characterization and crystal structures of some half-sandwich ruthenium(II) complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane containing π-acidic ancillary ligands

Abstract

The synthesis of a series of ruthenium(II) complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane L of type [RuL(X)Y(Z)]+ containing H, O2CCF3, CO, PPh3, dppe [1,2-bis(diphenylphosphino)ethane] or 2,6-Me2C6H3N≡C as auxiliary ligands are described where X = Y = CO, Z = Cl 1; X, Y = dppe, Z = Cl 2; X, Y = dppe, Z = H 3; X = CO, Y = PPh3, Z = H 4; X = Y = 2,6-Me2C6H3N≡C, Z = O2CCF3 5. All complexes were characterized by spectroscopic methods. The crystal structures of 1 and 4 as PF6 - salts have been determined. The two CO groups in complex 1 are in cis-fashion with a OC-Ru-CO angle of 90.1(3)°and the Ru-C distances are 1.850(6) and 1.893(6) Å. Complex 4 features one of the few ruthenium complexes containing three different piano-stool ligands, namely, CO, PPh3 and H. The measured Ru-CO and Ru-H distances in 4 are 1.785(9) and 1.54(9) Å respectively.