Organogelators Based on TTF Supramolecular Assemblies: Synthesis, Characterization, and Conductive Property
摘要:
A closely related family of organogelators 1-2 appended one or two electroactive tetrathiafulvalene (TTF) residues, has been designed and readily synthesized by Sonogashira reactions. These compounds can gelate a variety of organic solvents in view of multiple intermolecular interactions, and compounds 2 with two TTF subunits exhibit higher gelation ability than their corresponding 1. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigation of the xerogels from toluene gave a visual image showing that fibrillar aggregates are entangled in three-dimensional network structures. The columnar TTF cores stacking in the fiber, evidenced by the mixed-valence states absorption at around 2000 nm in ultraviolet visible near-infrared (UV-vis-NIR) spectra, provide an efficient pathway for the electron conduction. Upon oxidized by iodine, these xerogels exhibit semiconductive behaviors with moderate levels of conductivity. Additionally, the electrical conductivity of doped-xerogels 2 is 1 order of magnitude higher than that of 1 under identical conditions.
The self-assembly of N-annulated perylene bisimides (N-PBIs) has demonstrated that the ability of these units to generate different polymorphs upon supramolecularpolymerization decreases as the length of the alkyl bridge separating the peripheral side chains and the central aromatic backbones decreases. The kinetically controlled supramolecularpolymerization of these N-PBIs has also been investigated