Fig. 3. Representative solid-state molecular structures of (a) Et3PO–Si(catBr)2, (b) Et3PO–Si(catBr)2–OPEt3, and (c) [K@18-crown-6][F-Si(catF)2], polymorph A; (d) selection of the unit cell of [K@18-crown-6][F-Si(catF)2], polymorph B, (e) [K@18-crown-6][F-Si(catBr)(catF)], and (f) [PPN][Cl-Si(catH)2], cation omitted for clarity (ellipsoids at 50% probability level, hydrogen atoms omitted for clarity).
