The diastereoisomeric forms of a mononuclear Ru(II) complex bearing a bis-phenanthroline Tröger’s base

The synthesis of a novel completely asymmetric mononuclear complex of ruthenium(II) bearing a chiral bis-phenanthroline Tröger’s base ligand 1 (TBphen2) is reported. The diastereoisomeric forms of [Ru(phen)2TBphen2]2+ (ΔS/ΛR=rac-2a and ΛS/ΔR=rac-2b) were separated through crystallization. A complete structure elucidation of the diastereoisomers in solution, including chirality assignment, was achieved by 1D and 2D NMR techniques. Photophysical characterization revealed no significant differences in the emission properties of rac-2a and rac-2b that closely resemble those of [Ru(phen)3]2+.