A Missing Rare‐Earth Oxide Halide Structure Now Observed For Scandium Oxide Iodide, ScOI

Single crystals of ScOI were obtained from the residue of a vacuum sublimation of crude ScI 3 . The colourless plates crystallize with a new structure type: Monoclinic, C 2/ m , Z = 8, a = 1933.3(6) pm, b = 386.10(8) pm, c = 722.4(2) pm, β = 93.51(3)°, V m = 538.2(3) cm 3 mol −1 . The structure represents a missing link between the YOF/SmSI type variants (CN of the metal ion 4+3, only 3 6 nets stacked) and the PbFCl and FeOCl structure types (only 4 4 nets stacked, CN 4+4 and 4+2, respectively). In ScOI there are 4 4 (Sc, O) and 3 6 nets (I) stacked such that Sc III has a coordination number of 4+3.