Design and synthesis of multidentate ligands via metal promoted C-N bond formation processes and their coordination chemistry

This presentation reports some novel examples of organic ring amination reactions via metal mediation. The organic transformations are highly regioselective and can be controlled by the proper selection of the mediator complex. The two isomeric organic ligands viz. HL¹ and HL² were isolated in their pure states by the removal of the metal ions. These were fully characterized. The ligand HL¹ has lowpKa, 8.5. Upon deprotonation, it behaves as a potentialbis chelating N,N,N-donors. The coordination chemistry of the HL¹ ligand involving some 3d-metal ions is described. Two unusual low-spin complexes of manganese(II) and iron(III) are reported. The ferric complex displayed a rhombic EPR while, the corresponding manganese compound showed a complex pattern due to hyperfine coupling. All the complexes displayed large number of redox responses. A brief mention about the future projection of this work is noted.