Synthesis and magnetic studies of pentagonal bipyramidal metal complexes of Fe, Co and Ni

Three mononuclear metal complexes [MII(L-N3O2)(MeCN)2][BPh4]2 (M = Fe, 1; Co, 2; Ni, 3) were isolated and structurally characterized. Magnetic studies revealed uniaxial magnetic anisotropy for 1 (D = −17.1 cm−1) and 3 (D = −14.3 cm−1) and easy-plane magnetic anisotropy for 2 (D = +36.9 cm−1). Slow magnetic relaxation was observed for complexes 1 and 2 under an applied magnetic field, both of which are dominated by a Raman process.