Synthesis and characterization of a high spin d6 Fe(II) complex with the tridentate ligand dipyrido(2,3-a:3′,2′-j)phenazine (dpop′)

A new bis-(N-tridentate) Fe(II) complex [Fe(dpop′)2](PF6)2 (dpop′=dipyrido(2,3-a:3′,2′-j)phenazine) was prepared and studied. The magnetic moment of the solid was determined as μ=5.2–4.9 BM and in CH3CN solution as μ=4.9 BM and indicate the high spin Fe(II) state. The electronic absorption spectrum displays a broad weak absorption MLCT transition at 602 nm (ε=3.8×103 M−1 cm−1), consistent with CT absorptions of other Fe(II) HS complexes. The cyclic voltammogram of the complex shows an irreversible Fe2+/3+ oxidation at +1.55 V and two dpop′0/−1 centered reductions at −0.20 and −0.59 V versus Ag/AgCl.