Abstract
A novel amphiphilic perylenetetracarboxylic diimide (PDI) derivative, N-(4′-benzo-15-crown-5-ether)-N-hexyl-1,7-di(4-tert-butyl-phenoxy)perylen-3,4,9,10-tetracarboxylic diimide (15C5PDI), has been synthesized and characterized. Dimerization of 15C5PDI is induced in CHCl3 solution with the present of K+, resulting in the formation of the slipped co-facial J-aggregates, as revealed by absorption and fluorescence spectroscopies. Analysis of the surface pressure–area (π–A) isotherms and spectral change for the monolayer formed at the air/water interface, disclosed that 15C5PDI molecules adopted the H-type aggregation mode with a face-to-face configuration and edge-on orientation on both the surface of pure water and K+ aqueous solution. Consequently, a particularly interesting fluorescence emission change from “switch-on” to “switch-off” could be observed upon aggregation that was accompanied by a transformation from strongly fluorescent J-type into non-fluorescent H-type packing of the 15C5PDI dyes. Depending mainly on the coordination bonding between 15-crown-5-ether groups and K+ ions, one dimensional nanofibrils formed on the surface of the K+ aqueous solution with a more closely arrangement of 15C5PDI molecules relative to those on pure water subphase revealed by the π–A isotherms and atomic force microscopy (AFM) images. X-ray diffraction studies indicate that the film crystallinity and general molecular order in the Langmuir–Blodgett (LB) films deposited from the KCl solution are improved effectively in comparison with those from pure water subphase. Furthermore, the conductivity of the LB films prepared in K+ solution is more than ca. 1 order of magnitude higher than those from water.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Colloids and Surfaces A: Physicochemical and Engineering Aspects
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.