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

Two coordination polymers, [Y(H2O)4(H3chhc)]·6H2O (1) and [Cu5(H2O)10(Hchhc)2]·4H2O (2) with H6chhc = 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(H2O)4]3+ units in 1 are interlinked by the triprotonated (H3chhc)3− anions in a η5μ4 bridging mode to form 2D (43)2(46·66·83) topological networks, which are stacked along [0 1 0] direction in ···ABAB··· fashion with the lattice H2O molecules sandwiched between layers. The pentameric [Cu5(H2O)10]10+ units in 2 are bridged by monoprotonated (Hchhc)5− anions in a η8μ6 fashion to generate a 3D MOF of an unprecendented (43)(45·67·83) topology with the lattice H2O 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 (J1 = 1.86 cm−1) with an isosceles triangular Cu3 unit (J2 = 5.86 cm−1).

[Y(H2O)4(H3chhc)]·6H2O (1) and [Cu5(H2O)10(Hchhc)2]·4H2O (2) (H6chhc = cyclohexane-1,2,3,4,5,6-hexacarboxylic acid) feature a 2D (43)2(46·66·83) network and an unprecendented (43)(45·67·83) MOF, respectively. The magnetic susceptibilities of 2 could be modeled to a linear Cu(II) chain (J1 = 1.86 cm−1) combined with an isosceles triangular Cu36+ trimer (J2 = 5.86 cm−1).Figure optionsDownload as PowerPoint slideResearch highlights
► 1 Features 2D network of a rare (43)2(46·66·83) topology. 2 Exhibits 3D MOFs of an unprecedented (43)(45·67·83) topology. Magnetic behaviour of 2 modeled to a linear Cu(II) chain combined with a trimer.