Structure and Magnetic Properties of a Two-dimensional Metal-Organic Framework: [Cu3(bpdc)4/2(pdon)2(H2O)6] · 2ClO4

Abstract

A unique 2D sheet metal-organic framework, [Cu3(bpdc)4/2(pdon)2(H2O)6]·2ClO4 (2), has been synthesized by the hydrothermal reaction of pdon with Cu(ClO4)2 (bpdc = 2,2´-bipyridyl-3,3´- dicarboxylate, pdon = 1,10-phenanthroline-5,6-dione). Compound 2 crystallizes in the orthorhombic chiral space group P21212, with the cell parameters: a = 12.3596(11), b = 25.978(2), c = 7.9585(7) Å , V = 2555.3(4) Å3 [R1 = 0.068 and wR2 = 0.172]. It represents a novel metal-organic framework comprising of the mixed ligands of pdon and bpdc, where the cupric atoms are bridged by alternating the μ2- and μ4-bpdc groups into two-dimensional positively charged layers. The bpdc ligand has resulted from the in situ oxidative carbon-carbon bond cleavage of the pdon ligand. Compound 2 displays antiferromagnetic interactions. Above 40 K, χm −1 obeys the Curie-Weiss law with C = 1.37 cm3 Kmol−1 and Θ = −13.95 K.