Polyhedral Clathrate Hydrates. XIV. The Structure of (CH3)3CNH2·9¾H2O

Abstract

The crystal structure of 16(CH3)3CNH2·156H2O has been determined from three-dimensional x-ray-diffraction data obtained at −30°C. The crystals are cubic, space group I4̄3d, with cell dimensions a=18.81±0.02 Å. The host framework of hydrogen-bonded water molecules consists of face-sharing heptakaidecahedra which have three square, nine pentagonal, two hexagonal and three heptagonal faces. The square and pentagonal faces also form octahedra which complete the space-filling arrangement. The amine molecules occupy the larger polyhedra as nonbonded guests undergoing marked oscillatory motion.