Ru(III), Pd(II), Pt(III), and Pt(IV) Complexes of a Novel 32-Membered Unsymmetrical Dinucleating Macrocyclic Ligand

Abstract

Reactions of [N12] macrocyclic ligand, L ·2HClO4, with RuCl3, PdCl2, K2[PtCl6], [K2PtCl4] as well as [M(Ph3P)2Cl2] (M = Pd or Pt), and [Ru(Ph3P)3Cl2] produces bimetallic complexes whose analytical data are consistent with the molecular formulae as Ru2LCl4(ClO4)2 (I), Pd2LCl2(ClO4)2 (II), Pt2LCl6(ClO4)2 (III), Pt2LCl2(ClO4)2 (IV) and Ru2LCl2(ClO4)2 (V). Reactions of the ligand with the precursors [M(Ph3P)2Cl2] (M = Pd or Pt), and [Ru(Ph3P)3Cl2], has released all the Ph3P ancillary ligand in solution. Magnetic moment, IR and UV-visible spectroscopic data confirms the encapsulation of metal ions in the macrocyclic cavities through chelation from aza groups of the unsymmetrical imine (─C═N─) and amine (C─NH─C) functions. The macrocyclic moiety has accommodated both the lower as well as higher oxidation states of metal ions, i.e., Ru(II), Ru(III), Pd(II), Pt(II), and Pt(IV), which shows its flexible nature and capability to form stable complexes.