Structural Design of Coordination Polymers Based on Manganese and Chromium Ions Bridged by Oxalate Ligands

Abstract

Abstract Coordination polymers based on oxalate-bridged {[MnIICrIII(oxalate)3]−}∞ complexes of (DAT-2H2+)(DCH[18]crown-6)2[MnII(CH3OH)CrIII(oxalate)3]−2(CH3OH)3 and (DABCO-H+)2(DABCO-2H2+)[MnII(CH3OH)(Cl−)CrIII(oxalate)3]2−2(CH3OH), where DAT, DABCO, and DCH[18]crown-6 denote 2,5-diaminotoluene, 1,4-diazabicyclo[2.2.2]octane, and cis-syn-cis-dicyclohexano[18]crown-6, respectively, were synthesized. The crystal structure of the former complex was composed of [MnII(Λ)(CH3OH)CrIII(Λ)(oxalate)3]− units, whereas that of the latter crystal was composed of [MnII(Λ)(CH3OH)(Cl−)CrIII(Δ)(oxalate)3]2− units. The large flexible supramolecular cation in the former provided the two-dimensional structure of [MnII(Λ)(CH3OH)CrIII(Λ)(oxalate)3]−, although the two-dimensional honeycomb structure of the {[MnII(Δ)CrIII(Λ)(oxalate)3]−}∞ and {[MnII(Λ)CrIII(Δ)(oxalate)3]−}∞ networks are often observed for the oxalate complexes. The round-shaped DABCO molecule in the latter induced a one-dimensional chain structure of [MnII(Λ)(CH3OH)CrIII(Δ)(oxalate)3]−. The former crystal showed a magnetic field dependence of magnetization typical for a spin-canting system.