Hydrogen-Bond Directed Cyanide-Bridged Supramolecular 2D and 1D Bimetallic Coordination Polymers: Synthesis, Crystal Structure, and Magnetic Properties

Abstract

By using K₂[Ni(CN)₄] as a building block and two Mn(III) compounds containing bicompartimental Schiff-base ligands as assembling segments, two new cyanide-bridged Ni–Mn complexes of the formula {[Mn(L¹)(H₂O)]₄[Ni(CN)₄]}[ClO₄]₂·2CH₃CN (1) and {[Mn(L²)(H₂O)]₂[Ni(CN)₄]}·CH₃CN H₂O (2) (L¹ = N,N’-1,2-propylene-bis(3-methoxysalicylideneiminate; L² = N,N’-1,2-propylene-bis(3-ethoxysalicylideneiminate) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray analysis. Single Xray diffraction analysis revealed the cationic pentanuclear and neutral trinuclear structures for complexes 1 and 2, respectively, and indicated that the structure of the Schiff-base ligand had obvious influence on the structural types of the target cyanide-bridged complexes. Both cyanide-bridged complexes are self-complementary via coordinated aqua ligand from one complex and the free O₄ compartment from the neighboring complex, therefore giving supramolecular two-dimensional network and one-dimensional zig-zag chain structure. Study of magnetic properties revealed weak antiferromagnetic coupling within the Mn₂ dimer formed by the intermolecular hydrogen bond.