Logic information communication in a fluorescent molecular switch.

Based on the chemical-sensitive fluorescence emission behaviors of the molecular switch 4-bromo-5-methoxy-2-(2-pyridyl)thiazole (2-BMPT), the communication of logic information between two functional units has been realized. With the rational control of the protonation and coordination reaction of 2-BMPT, an upstream switching unit (a 1:2 demultiplexer) and two downstream data-processing units are involved and interconnected in the communication. The two output states of the 1:2 demultiplexer serve as the initial input states of the two parallel downstream data-processing units, which execute the information communication between the two circuit layers. Furthermore, in the parallel data-processing layer, the logic gates of INHIBIT and YES accomplish their specific logic functions. Therefore, a molecular cascade circuit composed of an upstream switch and two downstream processing units has been constructed based on the chemical-modulated fluorescence properties of 2-BMPT.

Orientational organization of organic semiconductors within periodic nanoscale silica channels: modification of fluorophore photophysics through hierarchical self-assembly.

Smart nanomaterials: The orientational organization of small organic semiconductors (anthracene, in this case) within periodic nanoscale silica channels (see figure) is achieved through a novel hierarchical self-assembly approach. This elicits interesting optical effects and improved mechanical properties that could be of potential importance for functional materials.A novel hierarchical organic-inorganic self-assembly approach is proposed in driving the orientational organization of small organic semiconductors (anthracene, in this case). A cationic surfactant with the special organic semiconductor anthracene at the hydrophobic tail was synthesized and used as both the structure-directing agent and as functional nanobuilding blocks. The self-assembly procedure was rapid and allowed for the uniform and molecular-level controllable organization of the organic semiconductors within periodic nanoscale silica channels. A range of techniques were used to demonstrate that the photophysical and photochemical nature of anthracene is significantly altered in the inorganic host, consistent with orientational packing of the organic semiconductors and excimer formation within the channels, from which energy migration and significant emission occur. The nanocomposite has also been demonstrated to show an interesting selective sensor function with respect to small solvent molecules. We suggest that this method could be used to drive the assembly of a wide range of organic semiconductor guests, offering the development of a variety of useful, smart nanomaterials that are able to self-assemble in a controllable and robust fashion.