New yttrium(III) and copper(II) coordination polymers with partially protonated cyclohexane-1,2,3,4,5,6-hexacarboxylato ligands: Synthesis, crystal structures and properties

摘要

Two coordination polymers, [Y(H_2O)_4(H _3chhc)]·6H_2O (1) and [Cu_5(H _2O)_(10)(Hchhc)_2]·4H_2O (2) with H_6chhc = cyclohexane-1,2,3,4,5,6-hexacarboxylic acid) represent rare examples of metal complexes with partially protonated cyclohexane-1,2,3,4,5,6- hexacarboxylato ligands. The [Y(H_2O)_4]~(3+) units in 1 are interlinked by the triprotonated (H_3chhc)~(3-) anions in a η~5μ_4 bridging mode to form 2D (4 ~3)_2(4~6·6~6·8 ~3) topological networks, which are stacked along [0 1 0] direction in ···ABAB··· fashion with the lattice H_2O molecules sandwiched between layers. The pentameric [Cu _5(H_2O)_(10)]~(10+) units in 2 are bridged by monoprotonated (Hchhc)~(5-) anions in a η~8μ _6 fashion to generate a 3D MOF of an unprecendented (4 ~3)(4~5·6~7·8~3) topology with the lattice H_2O molecules in channels. The temperature-dependent magnetic susceptibility data of 2 could be modeled to a combination of a linear chain of equally-spaced Cu(II) ions (J_1 = 1.86 cm~(-1)) with an isosceles triangular Cu_3 unit (J_2 = 5.86 cm ~(-1)).