Crystal structures and magnetic properties of two Co(II) coordination polymers created via in situ ligand synthesis

Abstract In this work, we present two new coordination polymers, [Co3(iBuOIPA)3(bps)(H2O)]n (1) and [Co2(iPrIPA)2(bps)]n (2) (bps = 4,4′-bipyridyl sulfide, iBuOIPA = 5-i-butoxyisophthalate, iPrIPA = 5-i-propoxyisophthalate), by the hydrothermal reactions of Co(OAc)2 4H2O and 4,4′-bipyridyl disulfide (bpds) with iBuOIPA or iPrIPA, respectively. Both crystal structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra and TG analyses. Interestingly, for 1 and 2, the starting bpds ligands were wholly transformed into bps. Polymer 1 displays a 3D network constructed from binuclear cobalt nodes while polymer 2 features a 2D infinite layer consisting of cobalt dimers. These results demonstrate that the existence of electron-donating groups in isophthalate derivatives plays a significant role during the self-assembly of polymers. Moreover, both 1 and 2 exhibit remarkable magnetic properties, which were investigated and discussed in detail, showing a good prospect in magnetic and energy storage devices.