Electronic properties of the S = 5/2 Mn(II) complexes [Mn{PhC(O)NP(O)PPh2}(N,N)(NO3)], (N,N) = phenanthroline, neocuproine, 2,2′-bipyridine

Abstract

The synthesis, as well as the structural and electronic properties of the [Mn(O,O)(N,N)(NO3)] complexes, (O,O) = {PhC(O)NP(O)PPh2}−, (N,N) = phenanthroline (1), neocuproine (2) and 2,2′-bipyridine (3) is reported. The three complexes were structurally characterized by X-ray crystallography, and complexes 1 and 2 were shown to be closer to octahedral, whereas 3 to trigonal prismatic. The zero-field splitting parameters of these S = 5/2 systems were determined by X- and Q-band EPR spectroscopy, revealing a small but significant difference in the magnitude of |D| for complex 3 (0.18 cm−1) compared to those of 1 and 2 (0.14 and 0.12 cm−1, respectively). These differences are attributed to the structural and electronic properties of complexes 1–3. The latter were probed by DFT calculations, which showed different DSOC contributions among the three complexes.