title: Kinetics and solvent-dependent thermodynamics of water capture by a fullerene-based hydrophobic nanocavity.
abstract: Kinetic and thermodynamic properties of water encapsulation from organic solution by an open-cage [60]fullerene derivative have been investigated. 2D exchange NMR spectroscopy (EXSY) measurements were employed to determine the association and dissociation constants at 300-330 K (k(a) = 4.3 M(-1) × s(-1) and k(d) = 0.42 s(-1) at 300 K) in 1,1,2,2-tetrachloroethane-d(2) as well as the activation energies (E(a,ass) = 27 kJ mol(-1), E(a,diss) = 50 kJ mol(-1)). The equilibrium constants and thermodynamic parameters in various solvents (benzene-d(6), 1,2-dichlorobenzene-d(4), and dimethylsulfoxide-d(6)) were estimated using 1D-(1)H NMR spectroscopy. The parameters were dependent on the polarity of the solvent; ΔH depended linearly on the solvent polarity, becoming increasingly unfavorable as polarity increased. Mixtures of polar dimethylsulfoxide-d(6) in less polar 1,1,2,2-tetrachloroethane-d(2) showed a similar trend.
authors.affiliation: Department of Chemistry, Columbia University, New York, New York 10027, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Frunzi
authors.forename: Anne M
authors.initials: AM
authors.lastname: Baldwin
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shibata
authors.forename: Sho-Ichi
authors.initials: S
authors.lastname: Iwamatsu
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Lawler
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Turro