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

Abstract

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.

Graphical Abstract

Keywords:

• Fe(III) complex
• Isonicotinamide
• Crystal structure
• Hydrogen bonds
• IR spectra

Funding

This work was supported by the Slovak Grant Agency [VEGA 1/0056/13 and APVV-0014-11].