title: Crown ethers at the aqueous solution-air interface. Part 2. Electrolyte effects, ethylene oxide hydration and temperature behaviour.
abstract: Vibrational Sum Frequency Spectroscopy (VSFS) was employed to study adsorbing films of 4-Nitro Benzo-15-Crown-5 (NB15C5) and Benzo-15-Crown-5 (B15C5) at the aqueous solution-air interface. The surface of the solution is strongly influenced by the presence of crown ether species. Changes in the orientation of NB15C5 were monitored as a function of solution concentration, by targeting the ratio of peak intensities of the CN and NO(2) vibrational modes. The water of hydration has also been probed as a function of crown concentration, salt concentration, and temperature. The latter study strongly suggests that the surface can be treated as a charged interface, and that the associated ordered water decreases with increasing ionic strength of the bulk solution.
authors: School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, 100 44, Sweden.
authors: Petru
authors: P
authors: Niga
authors: C Magnus
authors: CM
authors: Johnson
authors: Jeremy G
authors: JG
authors: Frey
authors: Mark W
authors: MW
authors: Rutland