title: 13C chemical shifts of propane molecules encaged in structure II clathrate hydrate.
abstract: Experimental NMR measurements for (13)C chemical shifts of propane molecules encaged in 16-hedral cages of structure II clathrate hydrate were conducted to investigate the effects of guest-host interaction of pure propane clathrate on the (13)C chemical shifts of propane guests. Experimental (13)C NMR measurements revealed that the clathrate hydration of propane reverses the (13)C chemical shifts of methyl and methylene carbons in propane guests to gaseous propane at room temperature and atmospheric pressure or isolated propane, suggesting a change in magnetic environment around the propane guest by the clathrate hydration. Inversion of the (13)C chemical shifts of propane clathrate suggests that the deshielding effect of the water cage on the methyl carbons of the propane molecule encaged in the 16-hedral cage is greater than that on its methylene carbon.
authors.affiliation: Methane Hydrate Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Toyohira-ku, Sapporo, Japan. m.kida@aist.go.jp
authors.forename: Masato
authors.initials: M
authors.lastname: Kida
authors.forename: Akira
authors.initials: A
authors.lastname: Hori
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Sakagami
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takeya
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kamata
authors.forename: Nobuo
authors.initials: N
authors.lastname: Takahashi
authors.forename: Takao
authors.initials: T
authors.lastname: Ebinuma
authors.forename: Hideo
authors.initials: H
authors.lastname: Narita