Reaction medium pH dependent existence of MnII bound [ON] donor zwitterionic chelating ligand and self-assembly of hydroxido-bridged Mn 4IIcluster

Abstract

A mononuclear MnN4O2 complex with two zwitterionic ligands and a centrosymmetric tetranuclear μ3-OH-bridged self-assembled Mn4 cluster were synthesized and characterized by using the [NO(H)N] ligand Hophbip [2,6-bis(phenylmethyliminomethyl)-4- methylphenol], The reaction, in MeOH in the presence of NH4SCN and a lower stoichiometry of Mn(OAc)2H2O without any added base produces [MnII(HNbip)2(NCS)2] ·CH3CN (1·CH3CN). In the presence of NaOH and NH 4SCN in MeOH, the cluster [Mn4II(μ-bip) 2(μ3-OH)2(NCS)4] (2), featuring a stepped-cubane, was obtained through, hydroxido-brid.ge-driven hydroxido-bridge-driven dimerization of two μ3-OHbridged [Mn 2] fragments derived from. 1-CH3CN. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.