A ruthenium(II) complex having a ligand undergoing partial C = N cleavage and unusual double-bond shift and nonchirality

A novel six-coordinate ruthenium(II) complex 1, formulated as [Ru(bpy)2Lb]PF6⋅ C2H5OH (bpy = 2,2′-bipyridine), has been obtained and characterized. Ligand Lb in 1 comes from a chiral bis-Schiff-base ligand La which is condensed between sodium(I) salt of D- or L-phenylanine and terephthaldicarboxaldehyde. It is noted that ligand La undergoes partial C = N bond cleavage of Schiff-base unit forming a free aldehyde group at one end of phenyl ring, and an unusual proton migration, a C = N double-bond shift and subsequent nonchirality at the other end simultaneously in the presence of a ruthenium(II) ion.