Designed synthesis of a multimetallic system having Ru(4)Cu(2) core using trimetallic coordination of 2,2'-biimidazolate ion

Synthesis of a novel hexametallic compound, (bpy)(2)Ru(biim)](4)Cu(2)](ClO(4))(4), (bpy = 2,2'-bipyridine and biim = 2,2'-biimidazolate dianion) from a monometallic complex, (bpy)(2)Ru(biim)] and hydrated Cu(ClO(4))(2) is described. The X-ray structure consists of four octahedral ruthenium(II) centers arranged around a bimetallic Cu(2)-core. The four octahedral (bpy)(2)Ru(biim)] units arranged around the Cu(2)-moiety that resulted in a propeller shape arrangement. The results of cryomagnetic measurements on the di-copper complex indicate that the two Cu(II) ions are coupled antiferromagnetically through the two bridging biim ligands. The EPR spectrum of the complex showed a typical axial spectrum. Optical spectra and redox properties of are reported. An intense absorption at 525 nm is assigned as Ru(dpi) --> pi(*)(bpy) transition.