One-dimensional coordination polymer of N-(phosphonomethyl)iminodiacetic acid with iron(II)

A one-dimensional coordination polymer containing Fe2+ centres and N-(phosphonomethyl)iminodiacetate residues (H4pmida), [Fe(H2pmida)(H2O)2], was synthesised via the hydrothermal method and structurally characterised by single-crystal and powder X-ray diffraction, elemental analysis, infrared spectroscopy, thermal analysis and magnetic measurements. The crystal structure is formed by the close packing of one-dimensional ∞1[Fe(H2pmida)(H2O)2] neutral coordination polymers, which run along the [0 0 1] direction of the unit cell. Interactions between neighbouring polymers are assured by several strong and highly directional O–H⋯O hydrogen bonds, described by a C54(11) graph set motif, involving the water molecules, the carboxylic acid group and the protonated phosphonate moiety.