Reaction Medium pH Dependent Existence of Mn II Bound [ON] Donor Zwitterionic Chelating Ligand and Self‐Assembly of Hydroxido‐Bridged Mn II 4 Cluster

A mononuclear MnN 4 O 2 complex with two zwitterionic ligands and a centrosymmetric tetranuclear μ 3 ‐OH‐bridged self‐assembled Mn 4 cluster were synthesized and characterized by using the [NO(H)N] ligand H OPh bip [2,6‐bis(phenylmethyliminomethyl)‐4‐methylphenol]. The reaction in MeOH in the presence of NH 4 SCN and a lower stoichiometry of Mn(OAc) 2 · 4H 2 O without any added base produces [Mn II (H N bip) 2 (NCS) 2 ] · CH 3 CN ( 1· CH 3 CN). In the presence of NaOH and NH 4 SCN in MeOH, the cluster [Mn II 4 (μ‐bip) 2 (μ 3 ‐OH) 2 (NCS) 4 ] ( 2 ), featuring a stepped‐cubane, was obtained through hydroxido‐bridge‐driven dimerization of two μ 3 ‐OH‐bridged [Mn 2 ] fragments derived from 1· CH 3 CN.