title: Managing Hydrogen Bonding in Clathrate Hydrates by Crystal Engineering.
abstract: Methanol is one of the most common inhibitors for clathrate hydrate formation. Crystalline clathrate hydrates containing methanol were synthesized and analyzed by powder X-ray diffraction and13C NMR spectroscopy. The data obtained demonstrate that methanol can be a helper guest for forming structure I, structure II, and structure H clathrate hydrates, as long as the lattice framework contains NH4F. The latter acts as a lattice stabilizer by providing sites for strong hydrogen bonding of the normally disruptive methanol hydroxy group. NH4F and methanol can be considered key materials for crystal engineering of clathrate hydrates, as the modified lattices allow preparation of hydrates of non-traditional water-soluble guests such as alcohols and diols. Methanol takes on the role of an unconventional helper guest. This extends clathrate chemistry to a realm where neither hydrophobic guests nor high pressures are required. This also suggests that more stable lattices can be engineered for applications such as gas storage.
authors.affiliation: National Research Council Canada, Ottawa, ON, K1A0R6, Canada.|School of Applied Chemical Engineering, Major in Applied Chemistry, Kyungpook National University, Daegu, 41566, Korea.
authors.forename: Kyuchul
authors.initials: K
authors.lastname: Shin
authors.affiliation: National Research Council Canada, Ottawa, ON, K1A0R6, Canada.|Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany.
authors.forename: Igor L
authors.initials: IL
authors.lastname: Moudrakovski
authors.affiliation: National Research Council Canada, Ottawa, ON, K1A0R6, Canada.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Ratcliffe
authors.affiliation: National Research Council Canada, Ottawa, ON, K1A0R6, Canada.|Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: John A
authors.initials: JA
authors.lastname: Ripmeester
keywords: crystal engineering; hydrates; methanol; powder X-ray diffraction; water chemistry