Layered manganese and copper phosphonates with metamagnetism observed in Mn(2-pmp)(H2O)2·H2O (2-pmpH2 = 2-pyridylmethylphosphonic acid)

Compounds Mn(2-pmp)(H2O)2·H2O (1) and Cu(2-pmp)(H2O) (2) (2-pmp = 2-pyridylmethylphosphonate) with similar layered structures are reported, which show metamagnetism and antiferromagnetism at low temperature.