Fluoride crystal structures. Part 27. Seleninyl difluoride at –35 °C

Abstract

The structure of the title compound (m.p. 15 °C) has been determined by the heavy-atom method from 184 diffractometer reflections, measured at –35 °C by use of a nitrogen-gas cooling device, and refined by full-matrix least-squares methods to R 0.082. Crystals are orthorhombic, space group Pca2₁, a= 5.65(1), b= 7.46(1), c= 6.24(1)Å,Z= 4. In the structure each selenium atom has one close oxygen (Se–O 1.62Å) and two close fluorine neighbours (mean Se–F 1.70 Å) giving a pyramidal co-ordination. These units are then linked through two oxygen bridges (mean Se ⋯ O 2.76 Å) and one fluorine bridge (Se ⋯ F 3.03 Å) to form a layer arrangement perpendicular to [010]. with a much distorted octahedral co-ordination around the selenium atom.