Syntheses, structures and magnetism of four Ni(II)/Co(II) interpenetrating coordination polymers based on 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine

Abstract

Four novel interpenetrating coordination polymers have been hydrothermally synthesized based on a long flexible N-donor ligand (bibp) and different polycarboxylates, namely [Ni(1,3-bdc)(bibp)(H2O)]·0.5H2O (1), [Ni(btec)0.5(bibp)1.5]·H2O (2), [Co(btec)0.5(bibp)1.5]·H2O (3) and [Co(oba)(bibp)]·2H2O (4) (bibp=1,4-bis(4-(imidazole-1-yl)benzyl)piperazine, 1,3-bdc=1,3-benzenedicarboxylate, btec=1,2,4,5-benzenetetracarboxylate, oba=4,4′-oxybisbenzoate). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra and TG analyses. Compound 1 shows a 2-fold interpenetrating 3D framework with CdSO4 topology. Compounds 2 and 3 exhibit 2-fold interpenetrating pcu frameworks. Compound 4 is a 2D→3D interdigitated network formed from 2D→2D threefold interpenetrating motifs. In addition, the magnetic properties of compounds 1–4 have also been investigated in the temperature range 2–300K.