Cyanide-Bridged Polynuclear and One-Dimensional FeIII-MnIII/II Bimetallic Complexes Based-on Pentacyanoferrite(III) Building Block: Synthesis, Crystal Structures, and Magnetic Properties

Abstract

In this contribution, based-on the structurally confirmed pentacyanometallate (PPh₄)₂[Fe(CN)₅(imidazole)]·(imidazole)·H₂O (1) and the manganese compounds [Mn(L)(H₂O)₂]ClO₄ (L = N,N-ethylenebis(3-methoxysalicylideneiminate) or [Mn(MAC)(H₂O)Cl]ClO₄ (MAC = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo-[12.3.1]octadeca-1(18),2,12,14,16-

pentaene), two new cyanide-bridged bimetallic Fe^III-Mn^III/II complexes {[Mn(L)(H₂O)]₃[Fe(CN)₅(imidazole)]}(ClO₄) (2) and {[Mn(MAC)][Fe(CN)₅(imidazole)]·CH₃OH}_n (3) were successfully synthesized and characterized by elemental analysis, IR spectroscopy and X-ray structure determination. Single X-ray diffraction analysis reveals the cationic FeMn₃ tetranuclear entity for complex 2, which can be further assembled into supramolecular 1D ladder-like double chain by the strong intermolecular hydrogen bond interactions. For complex 3, it can be structurally characterized as neutral one-dimensional linear single infinite chain. The magnetic investigations discover the ferromagnetic coupling between the Fe^III-Mn^III units in complex 2 and the antiferromagnetic coupling in complex 3 between the Fe^III-Mn^II units through the bridging cyanide group, respectively.