From crystal to crystal: A reconstructive solid-state reaction

The crystal structure of the Lewis acid-base adduct of 2-chloro-2-boraindane and diethylether was determined by X-ray diffraction. After abstraction of the boron-coordinated Et₂O molecule in vacuo, the crystal and molecular structure of the solvent-free boraindane, earlier synthesized by Kaufmann and Schacht [1], was studied on the resulting crystalline material. The different crystal packing in both structures and a diffraction experiment on an oriented single crystal showed that the reaction is reconstructive and that a rearrangement of the molecules parallels the change in molecular geometry.