A Pyrazolate-Supported Fe₃(μ₃-O) Core: Structural, Spectroscopic, Electrochemical, and Magnetic Study

A comparison is made between the structural, spectroscopic, electrochemical, and magnetic properties of pyrazolate versus carboxylate complexes [Fe3(μ3(μ3O)(μ-LL)6Cl3]2− containing the Fe3(μ3-O)-motif. While the Fe3(μ3-O)-cores are structurally indistinguishable in the two types of complexes, their magnetic properties deviate from the expected values as a result of a through-pyrazole contribution to the overall antiferromagnetic exchange with J1/hc = −80.1 cm−1 and J2/hc = −72.4 cm−1, or J1/hc = 70.6 cm−1 and J2/hc = −80.8 cm−1, (Hex = −J1(S1S2 + S2S3) − J2S1S3). The magnetic properties of the pyrazolate complexes are further tuned by an antisymmetric exchange interaction term.