Divalent metal coordination polymers assembled from dual linkers – semirigid carboxyphenylpropionate and dipyridyl type molecule

Abstract

This work presents a serials of six metal(II) complexes assembled from dual linkers, i.e. previously unutilized semirigid 3-(4-carboxyphenyl)propionic acid (H₂cpp) and dipyridyl type molecules di(4-pyridyl)ethylene (bpe) or 1,2-bi(4-pyridyl)ethane (bpa). Single crystal X-ray diffraction reveals a diversity of the structures: with compound {[Cu(Hcpp)₂(bpe)]·2H₂O}_n (1) manifesting a metal–organic coordination chain with parallel pendent arms, {[Cu₂(cpp)₂(bpe)₂(H₂O)]·4H₂O}_n (2) displaying a three-fold interpenetrating (4,4) grid, {[Ni(cpp)(bpe)_1.5H₂O]}_n (3) featuring a self-interpenetrating metal–organic coordination framework, {[Ni(Hcpp)₂(bpa)₂(H₂O)₂]}_n (4) exhibiting a metal–organic coordination chain with vertical pendent arms, {[Co(Hcpp)₂(bpa)₂(H₂O)₄}_n (5) affording a metal–organic coordination linear chain, and {[Co₂(cpp)₂(bpa)_1.5H₂O]}_n (6) affording a metal–organic coordination framework with pillared layers. It is shown that the semirigid carboxyphenylpropionate bears diverse metal–organic frameworks (MOFs) with low porosity resulting from the penetration of coordination networks. Magnetic measurement reveals that 6 presents weakly antiferromagnetic behavior.