Triclinic modification of diaqua­bis­(5-carb­oxy-1H-imidazole-4-carboxyl­ato-κ2N3O4)iron(II)

摘要

The title compound, [Fe(C5H3N2O4)2(H2O)2], is a triclinic modification of a monoclinic form recently reported by Du et al. [Acta Cryst. (2011), E>67, m997]. The Fe^II ion lies at an inversion center and is coordinated by two N and two O atoms from two 5-carb­oxy-1H-imidazole-4-carboxyl­ate ligands in trans positions, together with two water mol­ecules, completing a slightly distorted octahedral coordination. Inter­molecular N—H⋯O hydrogen bonding between the N—H group of the imidazole ring and the deprotonated carboxyl­ate group builds a chain of 5-carb­oxy-1H-imidazole-4-carboxyl­ate anions along the [101] direction. The water molecules form intermolecular hydrogen bonds to O—C and O=C sites of the carboxylate group in adjacent layers.