Divalent copper trans-1,4-cyclohexanedicarboxylate coordination polymers with isomeric dipyridylamide ligands: new pillared and self-penetrated binodal networks

Abstract

Hydrothermal synthesis has afforded a pair of divalent copper coordination polymers containing trans-1,4-cyclohexanedicarboxylate (t-14cdc) and one of two isomeric dipyridylamides, 3-pyridylnicotinamide (3-pna) or 3-pyridylisonicotinamide (3-pina). Both of these materials feature unprecedented 3-D topologies. [Cu(t-14cdc)(3-pna)]_n (1) manifests [Cu(t-14cdc)]_n 4·8² layers featuring embedded anti–syn axial–equatorial bridged [Cu(OCO)]_n chain motifs, pillared by anti-conformation 3-pna ligands into a new yet very simple binodal 3,5-connected (4·6·8)(4·6⁶·8³) network topology. {[Cu₂(t-14cdc)₂(3-pina)₂(H₂O)]·5H₂O}_n (2) shows two different copper/t14cdc chain motifs with isolated copper ions and {Cu₂O₂} dimeric units, respectively. These are linked together by 3-pina ligands to afford a new self-penetrated 4,6-connected binodal net with (4·6⁴·8)₂(4²·6¹²·8) topology. Variable temperature magnetic susceptibility experiments reveal very weak ferromagnetism (g = 2.01(1), J = 0.04(1) cm⁻¹) along the [Cu(OCO)]_n chains in 1 and weak antiferromagnetism (g = 1.906(3), J = −3.4(3) cm⁻¹) within the {Cu₂O₂} dimeric units in 2. Thermal properties are also presented.