Designed synthesis and supramolecular architectures of furan-substituted perylene diimide

Progress in the synthesis of perylene bisimide dyes

Rapid progress in the synthesis of perylene bisimide dyes gave an old scaffold new life.

Novel fluorescent probes for the fluoride anion based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives

The fluoride anion (F⁻) sensing abilities of 1-hydroxyl-3,4,9,10-tetra (n-butoxyloxycarbonyl) perylene (probe 1) and 1-hydroxyl-mono-five-membered S-heterocyclic annulated tetra (n-butoxyloxycarbonyl) perylene (probe 2) were studied through visual detection experiments, UV-Vis, fluorescence, and ¹H NMR titrations. The probes were sensitive and selective for distinguishing F⁻ from other anions (Cl⁻, Br⁻, I⁻, SO₄⁻, PF₆⁻, H₂PO₄⁻, BF₄⁻, ClO₄⁻, OH⁻, CH₃COO⁻, and HPO₄²⁻) through a change of UV-Vis and fluorescence spectra. The absorption and fluorescence emission properties of the probes arise from the intermolecular proton transfer (IPT) process between a hydrogen atom on the phenolic O position of probe and the F⁻ anion. The sensing mechanism was supported by theoretical investigation. Moreover, probe-based test strips can conveniently detect F⁻ without any additional equipment, and they can be used as fluorescent probes for monitoring F⁻ in living cells.

The fluoride anion (F⁻) sensing abilities of two fluorescent probes based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives were studied through visual detection experiment, UV-Vis, fluorescence, and ¹H NMR titrations.

Self-assembly of functional molecules into 1D crystalline nanostructures

Self-assembled functional nanoarchitectures are employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials usage efficiency, low energy consumption, and high-performance devices. One-dimensional (1D) crystalline nanostructures, especially molecule-composed crystalline nanostructures, attract significant attention due to their fascinating infusion structure and functionality which enables the easy tailoring of organic molecules with excellent carrier mobility and crystal stability. In this review, we discuss the recent progress of 1D crystalline self-assembled nanostructures of functional molecules, which include both a small molecule-derived and a polymer-based crystalline nanostructure. The basic principles of the molecular structure design and the process engineering of 1D crystalline nanostructures are also discussed. The molecular building blocks, self-assembly structures, and their applications in optical, electrical, and photoelectrical devices are overviewed and we give a brief outlook on crucial issues that need to be addressed in future research endeavors.

Self-assembly of intramolecular charge-transfer compounds into functional molecular systems

Highly polarized compounds exhibiting intramolecular charge transfer (ICT) are used widely as nonlinear optical (NLO) materials and red emitters and in organic light emitting diodes. Low-molecular-weight donor/acceptor (D/A)-substituted ICT compounds are ideal candidates for use as the building blocks of hierarchically structured, multifunctional self-assembled supramolecular systems. This Account describes our recent studies into the development of functional molecular systems with well-defined self-assembled structures based on charge-transfer (CT) interactions. From solution (sensors) to the solid state (assembled structures), we have fully utilized intrinsic and stimulus-induced CT interactions to construct these functional molecular systems. We have designed some organic molecules capable of ICT, with diversity and tailorability, that can be used to develop novel self-assembled materials. These ICT organic molecules are based on a variety of simple structures such as perylene bisimide, benzothiadiazole, tetracyanobutadiene, fluorenone, isoxazolone, BODIPY, and their derivatives. The degree of ICT is influenced by the nature of both the bridge and the substituents. We have developed new methods to synthesize ICT compounds through the introduction of heterocycles or heteroatoms to the π-conjugated systems or through extending the conjugation of diverse aromatic systems via another aromatic ring. Combining these ICT compounds featuring different D/A units and different degrees of conjugation with phase transfer methodologies and solvent-vapor techniques, we have self-assembled various organic nanostructures, including hollow nanospheres, wires, tubes, and ribbonlike architectures, with controllable morphologies and sizes. For example, we obtained a noncentrosymmetric microfiber structure that possessed a permanent dipole along its fibers' long axis and a transition dipole perpendicular to it; the independent NLO responses of this material can be separated and tuned spectroscopically and spatially. The ready processability and intrinsically high NLO efficiency of these microfibers offer great opportunities for applications in photonic devices. We have also designed molecular sensors based on changes in the efficiency of the ICT process upon complexation of an analyte with the D or A moieties in the ICT compounds. Such sensors, which display evident Stokes shifts or changes in quantum yields or fluorescence lifetimes, have promise for applications in chemical and biological recognition and sensing. In this Account, we shed light on the structure-function relationships of these functional molecular systems with well-defined self-assembled structures based on ICT interactions. The encouraging results that we have obtained suggest that such self-assembled ICT molecular materials can guide the design of new nanostructures and materials from organic systems, and that these materials, across a range of compositions, sizes, shapes, and functionalities, can potentially be applied in the fields of electronics, optics, and optoelectronics.