Preparation and study of analogs of dipyrido[3,2-a:2',3'-c]phenazine and their ruthenium(II) and copper(I) complexes

A series of homoleptic and heteroleptic Ru(II) complexes of several tridentate analogs of dipyrido[3,2-a:2',3'-c]phenazine (8a-c) were prepared, and their photophysical, electrochemical, DNA-intercalation, and DNA-cleavage properties were examined. The ligands were prepared through synthesis of their 1,10-phenanthroline analogs, oxidation of the analogs at C5 and C6 with KBr in HNO3/H2SO4, and condensation of the quinones with o-phenylenediamine derivatives. The homoleptic complexes were prepared with [RuCl3(H2O) 3] while the heteroleptic complexes were prepared with [Ru(tpy)Cl 3] under microwave conditions. The heteroleptic Ru(II) tpy-containing complex of 8b was found to cleave DNA upon irradiation in presence of 3O2. There was a small bathochromic shift in the metal-to-ligand charge-transfer (MLCT) band due to the geometry of the complex relative to the MLCT bands of previously studied tris-bidentate complexes. There was a larger bathochromic shift of the MLCT band upon elaboration of the ligand near the coordination site as opposed to the phenazine subunit. Elaboration at the phenazine subunit with a benzo group did increase the luminescence lifetime of the complexes.;A series of air-stable homoleptic Cu(I) complexes of bidentate analogs of dipyrido[3,2-a:2',3'-c]phenazine (47a-d, 48a-c, 49a-c) containing methyl, phenyl, and chloro substituents ortho to the coordinating nitrogens were prepared, and photophysical and electrochemical properties of the complexes were examined. The ligands were prepared in a similar fashion to the tridentate ligands 8a-c, but oxidation of the phenyl-substituted ligands required I2O 5 as the oxidant. The complexes were prepared with [Cu(MeCN)4](PF 6). The MLCT bands of the complexes were comparable in energy to (Ru(II) complexes of bidentate dppz analogs.;A series of dppz analogs which coordinate through cyclometallation (64aH, 64bH, 64cH) were prepared along with their Ru(II) complexes, and photophysical and electrochemical properties of the complexes were examined. The ligands were prepared in a similar fashion to the tridentate ligands 8a-c, but oxidation required I2O5 as the oxidant. The complexes were prepared with [Ru(bpy-d8) 2Cl2. Both MLCT bands for the complexes of 64a and 64b were lower in energy than the MLCT band of [Ru(bpy) 2(dppz)]2+.