Signaling Recognition Events with Fluorescent Sensors and Switches.

Fluorogenic and chromogenic chemosensors and reagents for anions.

Azobenzene undergoes trans → cisisomerization when irradiated with light tuned to an appropriate wavelength. The reverse cis →transisomerization can be driven by light or occurs thermally in the dark. Azobenzene's photochromatic properties make it an ideal component of numerous molecular devices and functional materials. Despite the abundance of application-driven research, azobenzene photochemistry and the isomerization mechanism remain topics of investigation. Additional substituents on the azobenzene ring system change the spectroscopic properties and isomerization mechanism. This critical review details the studies completed to date on the 3 main classes of azobenzene derivatives. Understanding the differences in photochemistry, which originate from substitution, is imperative in exploiting azobenzene in the desired applications.

Photoisomerization in different classes of azobenzene

The goal of artificial photosynthesis is to use the energy of the sun to make high-energy chemicals for energy production. One approach, described here, is to use light absorption and excited-state electron transfer to create oxidative and reductive equivalents for driving relevant fuel-forming half-reactions such as the oxidation of water to O2 and its reduction to H2. In this “integrated modular assembly” approach, separate components for light absorption, energy transfer, and long-range electron transfer by use of free-energy gradients are integrated with oxidative and reductive catalysts into single molecular assemblies or on separate electrodes in photelectrochemical cells. Derivatized porphyrins and metalloporphyrins and metal polypyridyl complexes have been most commonly used in these assemblies, with the latter the focus of the current account. The underlying physical principleslight absorption, energy transfer, radiative and nonradiative excited-state decay, electron transfer, proton-coupled elec...

Chemical approaches to artificial photosynthesis

http://alpha.chem.umb.edu/chemistry/ch612/documents/CastellanoCoordChemrev.pdf

John Olmsted

Papers

Calorimetric determinations of absolute fluorescence quantum yields

Absolute luminescence yield of cresyl violet. A standard for the red

Photochemical determination of the solubility of oxygen in various media.

Fluorescence of polymerized diacetylene bilayer films

Factors affecting cage escape yields following electron-transfer quenching