Structural and mechanistic studies of co-ordination compounds. Part 26. Synthesis and characterization of some octahedral complexes of ruthenium-(II) and -(III) with macrocyclic quadridentate thioethers

Abstract

A series of ruthenium-(II) and -(III) complexes of the macrocyclic quadridentate thioethers 1,4,8,11-tetrathiacyclotetradecane (L¹) and 1,4,7,10-tetrathiacyclotridecane (L²) has been prepared and characterized. Complexes containing the 14-membered ring, L¹, viz. trans-[RuL¹X₂]⁺(X = Cl or Br), trans-[RuL¹X₂](X = Cl, Br, I, NCS, N₃, or NO₂), and trans-[RuL¹X(OH₂)]⁺(X = Cl or Br), have the two remaining unidentate ligands trans to each other. However, the 13-membered ring, L², co-ordinates to the central metal ion in a folded manner to give cis-[RuL²Cl₂]⁺, cis-[RuL²X₂](X = Cl, Br, I, NCS, NO₂, or N₃), and cis-[RuL²Cl(OH₂)]⁺. All the ruthenium(III) complexes are low spin and the ruthenium(II) complexes diamagnetic. They are all monomeric species. The electronic and i.r. absorption spectra of these complexes are discussed.