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

In this work, we present two new coordination polymers, [Co-3(iBuOIPA)(3)(bps)(H2O)](n) (1) and [Co-2(iPrI-PA)(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) 4H(2)O 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 selfassembly 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.