Synthesis, crystal structure and properties of chloridotetrakis(pyridine-3-carbonitrile)thiocyanatoiron(II)

Reaction of FeCl2 · 4H2O with KSCN and 3-cyanopyridine (pyridine-3-carbonitrile) in ethanol accidentally leads to the formation of single crystals of Fe(NCS)(Cl)(3-cyanopyridine)4 or [FeCl(NCS)(C6H4N2)4]. The asymmetric unit of this compound consists of one FeII cation, one chloride and one thiocyanate anion that are located on a fourfold rotation axis as well as of one 3-cyanopyridine coligand in a general position. The FeII cations are sixfold coordinated by one chloride anion and one terminally N-bonding thiocyanate anion in trans-positions and four 3-cyanopyridine coligands that coordinate via the pyridine N atom to the FeII cations. The complexes are arranged in columns with the chloride anions, with the thiocyanate anions always oriented in the same direction, which shows the non-centrosymmetry of this structure. No pronounced intermolecular interactions are observed between the complexes. Initially, FeCl2 and KSCN were reacted in a 1:2 ratio, which lead to a sample that contains the title compound as the major phase together with a small amount of an unknown crystalline phase, as proven by powder X-ray diffraction (PXRD). If FeCl2 and KSCN is reacted in a 1:1 ratio, the title compound is obtained as a nearly pure phase. IR investigations reveal that the CN stretching vibration for the thiocyanate anion is observed at 2074   cm − 1, and that of the cyano group at 2238   cm − 1, which also proves that the anionic ligands are only terminally bonded and that the c...

Source: Acta Crystallographica Section E - November 21, 2023 Category: Chemistry Authors: M ü ller-Meinhard, A. Jess, I. N ä ther, C. Tags: synthesis crystal structure mixed iron thiocyanate chloride complex powder diffraction thermal properties research communications Source Type: research