Synthesis, magnetic susceptibility, and spectroscopic properties of single- and mixed-valence iron oxalate, squarate, and dihydroxybenzoquinone coordination polymers

Magnetic susceptibility data for several Fe(II) coordination polymers containing oxalate or squarate dianions are reported in the temperature range 4.2-300 K. Low temperature magnetism of Fe(C2O4)(H2O)2 is dominated by intrachain ordering near 32 K followed by the onset of interchain long-range order slightly below this temperature. Susceptibility data for Fe(C4O4)(H2O)2 and Fe(C4O4)(C5H5N)2-2H2O show no detectable spin exchange in the temperature range studied.