Syntheses, crystal structures, and IR spectra of isonicotinamide-isonicotinamidium bis(isonicotinamide)-tetrakis(isothiocyanato)ferrate(III) and isonicotinamidium chloride

Reaction of iron(III) thiocyanate with isonicotinamide (inia) in ethanol leads to formation of a dark red, air stabile crystalline iron(III) compound of composition [iniaH·inia][Fe(inia)2(NCS-N)4]. Single-crystal X-ray diffraction analysis shows the triclinic P–1 space group with unit cell parameters: a = 8.2440(4) Å, b = 9.5540(3) Å, c = 11.2590(5) Å, α = 93.945(4)°, β = 95.554(4)°, γ = 96.285(3)°, and Z = 1. The iron compound contains [iniaH·inia]+ cations and [Fe(inia)2(NCS-N)4]– anions, which are held together by ionic interactions and hydrogen bonding. The Fe(III) is octahedrally coordinated by six nitrogens, four from NCS– in the equatorial plane and two from inia occupying axial positions. The [iniaH]Cl has been formed by reaction of inia with hydrochloric acid. [iniaH]Cl crystallized in the monoclinic C2/c space group with unit cell parameters: a = 25.156(5) Å, b = 5.095(1) Å, c = 12.747(3) Å, and Z = 8. Both compounds have also been characterized by elemental analyses and infrared spectroscopy. Structural and infrared spectral data are compared with data of similar compounds in the literature.