The cubic superstructure-I of tetrabutylammonium fluoride (C4H9)4NF•29.7H2O clathrate hydrate

The crystal structure of (C4H9)(4)NF center dot 29.7H(2)O clathrate hydrate (ionic clathrate) determined by X-Ray analysis is reported. The structure is cubic, I(4)over bar 3>d, a = 24.375(3) angstrom (150 K). Its idealized water framework is analogous to that of cubic structure-I of gas hydrates but with eight-fold unit cell, that is a superstructure of cubic structure-I. This is the last structure found in the binary system (C4H9)(4)NF-H2O which was not characterized by X-ray analysis earlier. The structure features of the compound under investigation and others existing in H2O-(C4H9)(4)NF binary system are discussed.