Controllable supramolecular self-assemblies (rods–wires–spheres) and ICT/PET based perylene probes for palladium detection in solution and the solid state†
Abstract
Control over the self-assembly of bay functionalized perylene diimides and the response of these self-assembled materials towards analytes in mixed aqueous–organic media is important to consider the potential of this intriguing dye family in supramolecular chemistry. Herein, we have designed and synthesized allylcarbonate-functionalized perylene diimide AC-PDI which shows solvent dependent supramolecular nanostructures and could readily self-assemble into nanorods of tens of μm in length in CH3CN, but the length of the rods drammatically decreased to 0.8–1.2 μm in a H2O : CH3CN (1 : 1, v/v) mixture. Interestingly, AC-PDI self-assembles into nanowires of several tens of μm in length in a 30% H2O:DMSO mixture and forms only nanospheres in ethyl acetate. AC-PDI can be used as a near-infrared (NIR) colorimetric (λabs 685 nm) and fluorescent (λem 530/570 nm) probe for selective detection of Pd0 [LOD = 39 nM (UV); 45 nM (FI)]. Furthemore, TLC strips coated with the AC-PDI probe could detect 0.58 pg cm−2 of Pd0 in the solid state. The mechanism of interaction of AC-PDI with Pd0 has been confirmed by 1H NMR titration, kinetic and morphological studies.