Influence of the Capping Ligands on the Self‐Assembly of Cyanido‐Bridged Mn(II)‐Fe(III) Aggregates: Synthesis, Crystal Structures, Electrochemical and Magnetic Properties

Reaction of Mn(II) salts with a meridional tricyanido iron(III) linker, [Fe(bbp)(CN)3]2− (H2bbp=bis(2-benzimidazolyl)pyridine) was investigated in presence of two different N-donor blocking ligands. Two heterometallic Mn(II)/Fe(III) aggregates viz. [Mn(cptp)2][Fe(bbp)(CN)3] ⋅ 3H2O (1) (cptp=4’-(4-chlorophenyl)-2,2’ : 6’,2’’-terpyridine) and [Mn(CH3OH)2(μ-NC)3Fe(bbp)]n (2) are isolated and characterized by using analytical, spectroscopic, structural, electrochemical and magnetic investigations. Single crystal X-ray diffraction analysis show that compound 1 is a heterobimetallic complex salt, while compound 2 is a cyanido bridged Mn(II)−Fe(III) ladder shaped chain. The electrochemical behaviours of both compounds 1 and 2 exhibit multiple redox accessible states associated with the corresponding metal centres. Investigation of magnetic properties of 2 manifest interplay of antiferromagnetic interaction between low-spin Fe(III) and high-spin Mn(II) ions.