Langmuir films of the novel anion-capped amphiphilic benzodithia-15-crown-5 dye

The novel anion-capped amphiphilic benzodithia-15-crown-5 styryl dye forms relatively stable insoluble monolayers on distilled water (collapse pressur e is approx. 35 mN/m) and on the aqueous subphases containing alkali metal cations (38 mN/m) or heavy metal cations (33 or 31 mN/m for Ag+ or Hg2+), r espectively. Two types of the dye-cation complexes, depending on the nature of a particular cation in the aqueous subphase, have been distinguished by measuring surface pressure-molecular area and surface potential-molecular area isotherms, as well as observed by Brewster angle microscopy. The surfa ce-active and spectroscopic properties of the amphiphilic dye in monolayers in the presence of K+, Na+, Ca2+, Mg2+, Ag+ or Hg2+ cations in the aqueous subphases have been studied. (C) 2000 Elsevier Science S.A. All rights res erved.