Synthesis and crystal structure of tris[(dibenzo-18-crown-6-(tetrahydrofuran)potassium) hexakis(isothiocyanato)ferrate(III) 0.3 hydrate

Abstract

A new complex [K(Db18C6)(THF)]3+[Fe(NCS)6]3− · 0.31 H2O (I) was prepared and studied by X-ray diffraction (space group C2/c, a = 21.954, b = 26.496, c = 15.902 A, β = 102.24°, Z = 4; direct method, leastsquares refinement in the anisotropic approximation to R = 0.098 for 5944 independent reflections; CAD4 automated diffractometer, λMoKα). The [Fe(NCS)6]3− anion (on twofold axis) having a slightly distorted octahedral structure is connected by two K-S bonds with two complex cations connected by a twofold axis. Two independent complex cations [K(Db18C6)(THF)]+ are of the host-guest type, one being statistically disordered with respect to the twofold axis with site populations of 0.5. The coordination polyhedra of K+ are a distorted hexagonal bipyramid and pyramid.