This salt is prepared by treating an aqueous solution of ruthenium trichloride with 2,2'-bipyridine.  In this conversion, Ru(III) is reduced to Ru(II), and hypophosphorous acid is typically added as a reducing agent. [Ru(bpy)] is octahedral, containing a central low spin d Ru(II) ion and three bidentate bpy ligands. The Ru-N distances are 2.053(2), shorter than the Ru-N distances for [Ru(bpy)].  The complex is chiral, with D symmetry.  It has been resolved into its enantiomers.  In its lowest lying triplet excited state the molecule is thought to attain lower C symmetry, as the excited electron is localized primarily on a single bipyridyl ligand.