Crystals clathrate hydrates

The original X-ray studies of the gas clathrate hydrate structures were based on powder diffraction data, since the gas hydrates are notoriously difficult to obtain as single crystals. Clathrate hydrates formed by compounds which are liquids above 0°C, such as those of ethylene oxide and tetrahydrofuran, can be readily grown as large single crystals, and X-ray single crystal studies of both these hydrates have been carried out [787, 788]. 

Goldschleger lU, Kc nskaya G, Senekerimyan V, Janda KC, Apkarian VA (2008) Dynamical interrogation of the hydration cage of bromine in single crystal clathrate hydrates versus water. Phys Chem ChemPhys 10(48) 7226-7232. doi 10.1039/b811529j... 

A piperidene-based intermediate was found to crystallize as either an anhydrate or a hydrate, but the impurity profile of the crystallized solids differed substantially [26], Considerations of molecular packing led to the deduction that there was more void volume in the anhydrate crystal structure than in that of the hydrate form, thereby facilitating more clathration in the anhydrate than in the hydrate phase. This phenomenon was led to a decision to crystallize the hydrate form, since lower levels of the undesired impurity could be occluded and greater compound purity could be achieved in the crystallization step. 

In an oligonucleotide-drug hydrate complex, the appearance of a clathrate hydrate-like water structure prompt a molecular dynamics simulation (40). Again the results were only partially successful, prompting the statement, "The predictive value of simulation for use in analysis and interpretation of crystal hydrates remains to be established." However, recent molecular dynamics calculations have been more successful in simulating the water structure in Ae host lattice of a-cyclodextrin and P-cyclodextrin in the crystal structures of these hydrates (41.42). 

Clathrate Hydrate Crystallization for Clean Energy and Environmental Technologies... 

Knight, C.A. Rider, K. (2002). Free-growth forms of tetrahydrofuran clathrate hydrate crystals from the melt plates and needles from a fast-growing vicinal cubic crystal. Philosophical Magazine 82 (8), 1609-1632. 

Lee, J.D. Song, M. Susilo, R. Englezos, P. (2006b). Dynamics of Methane-Propane Clathrate Hydrate Crystal Growth from Liquid Water with or without the Presence of n-Heptane. Crystal Growth Design, 6 (6), 1428-1439. 

Mochizuki, T. (2003). Clathrate hydrate formation at liquid/liquid interface under shear water flow. J. Crystal Growth, 249, 372-380. 

Mochizuki, T. Mori, Y.H. (2006). Clathrate-hydrate film growth along water/hydrate-former phase boundaries - numerical heat-transfer study. J. Crystal Growth, 290 (2), 642-652. 

Ohmura, R. Shimada, W. Uchida, T. Mori, Y.H. Takeya, S. Nagao, S. Minagawa, H. Ebinuma, T. Narita, H. (2004). Clathrate hydrate crystal growth in liquid water saturated with a hydrate-forming substance variations in crystal morphology. 

Ohmura, R. Matsuda, S. Itoh, S. Ebinuma, T. Narita, H. (2005d). Clathrate Hydrate Crystal Growth in Liquid Water Saturated with a Guest Substance Observations in a Methane + Water System. Crystal Growth Design, 5(3), 953-957. 

Uchida, T. Ebinuma, T. Kawabata, J. Narita, H. (1999b). Microscopic observations of formation processes of clathrate-hydrate films at an interface between water and carbon dioxide. J. Crystal Growth, 204 (3), 348-356. 

The crystal chemistry of the clathrate hydrates is based upon 4-(rarely) and 5- and 6-membered-rings of linked... 

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