Channel polyhydrate (C2H5)4NF.11H2O

The phase diagram of the system (C₂H₅)₄NF–H₂O, has been studied. The polyhydrates (C₂H₅)₄NF·5H₂O and (C₂H₅)₄NF·11H₂O, which melt congruently at 24.8 and – 13.6 °C respectively, have been found in this system. The hydrate (C₂H₅)₄NF-11H₂O has a channel–cavity structure. Water and fluoride anions form a three-dimensional framework consisting of channels and cavities. The channels are filled with cations (C₂H₅)₄N⁺, and the cavities are vacant. The polyhydrate (C₂H₅)₄NF·11H₂O has the following crystallographic parameters: a = 12.393(3), b = 22.595(7) c = 11.483(3) A (T = –100°C), space group Pnnm, Z = 6.