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

摘要

Coordination polymers based on oxalate-bridged {[(MnCrIII)-Cr-II- (oxalate)(3)](-)}(infinity) complexes of (DAT-2H(2+))(DCH[18]crown-6)(2)[Mn-II(CH3OH)Cr-III(oxalate)(3)](-)(2)(CH3OH)(3) and (DABCO-H+)(2)(DABCO-2H(2+))[Mn-II(CH3OH)(Cl-)Cr-III(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-syncis-dicyclohexano[18]crown-6, respectively, were synthesized. The crystal structure of the former complex was composed of [Mn-II(Lambda)(CH3OH)Cr-III(Lambda)(oxalate)(3)](-) units, whereas that of the latter crystal was composed of [Mn-II(Lambda)(CH3OH)(Cl-)-Cr-III (Delta)(oxalate)(3)](2-) units. The large flexible supramolecular cation in the former provided the two-dimensional structure of [Mn-II(Lambda)(CH3OH)Cr-III(Lambda)(oxalate)(3)](-), although the two-dimensional honeycomb structure of the {[Mn-II(Delta)Cr-III(Lambda)-(oxalate)(3)](-)}infinity and {[Mn-II(Lambda)Cr-III(Delta)(oxalate)(3)](-)}(infinity) networks are often observed for the oxalate complexes. The round-shaped DABCO molecule in the latter induced a one-dimensional chain structure of [Mn-II(Lambda)(CH3OH)Cr-III(Delta)(oxalate)(3)](-). The former crystal showed a magnetic field dependence of magnetization typical for a spin-canting system.