title: Water Entrapped inside Fullerene Cages: A Potential Probe for Evaluation of Bond Polarization.
abstract: The concept of the bond polarization is a useful tool to understand chemical reactions and fundamental properties of compounds. However, experimental considerations are limited owing to its difficulty of reliable description. We demonstrated that geometrically isolated H2O inside the cage of fullerene C60is a possible probe to evaluate the polarization degree of covalent bonds C(C60)-X (X=heteroatom) on the C60cage. The1H NMR relaxation times of entrapped H2O have been systematically measured at variable temperatures for H2O@C60X (X=CR2, NR, O, and O2). The results followed in the order of electronegativities of C (2.55), N (3.04), and O (3.44), indicating that entrapped H2O can sensitively respond to the degree of the bond polarization.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Hashikawa
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Michihisa
authors.initials: M
authors.lastname: Murata
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Wakamiya
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan. yasujiro@scl.kyoto-u.ac.jp.
authors.forename: Yasujiro
authors.initials: Y
authors.lastname: Murata
keywords: NMR spectroscopy; bond polarization; fullerenes; relaxation times; water