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

Abstract

The novel anion-capped amphiphilic benzodithia-15-crown-5 styryl dye forms relatively stable insoluble monolayers on distilled water (collapse pressure 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 Hg 2+), respectively. 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 surface-active and spectroscopic properties of the amphiphilic dye in monolayers in the presence of K +, Na +, Ca 2+, Mg 2+, Ag + or Hg 2+ cations in the aqueous subphases have been studied.