Construction of a new magnetic coordination polymer through an unusual Fe-mediated in situ redox reaction

A new iron(II) coordination polymer, namely [Fe(Hmna)2]n (1; H2mna = 2-mercaptonicotinic acid), has been synthesized under hydrothermal condition through an unusual Fe-mediated in situ redox reaction. Complex 1 was characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and elemental analyses as well as thermogravimetric analysis. 1 generally exhibits one-dimensional linear structures bridged through the sulfur and oxygen donors of organic ligand, which are further attached into a three-dimensional supramolecular structure via intermolecular hydrogen bond interactions. The construction of compound 1 involved an unusual in situ Fe(III)/Fe(II) redox reaction, which was confirmed by X-ray photoelectron spectroscopy. In addition, magnetic measurements for 1 indicated the presence of overall antiferromagnetic interactions within structure.