Dual Photoisomerization on Distinct Potential Energy Surfaces in a UV-Absorbing Rhodopsin

Impacts of retinal polyene (de)methylation on the photoisomerization mechanism and photon energy storage of rhodopsin.

Ab initio multiconfigurational quantum chemical methodology combined with molecular mechanics (CASPT2//CASSCF/AMBER) was applied to probe impacts of retinal protonated Schiff base (RPSB) polyene methylation and/or demethylation on the mechanism of photochemical isomerization in bovine rhodopsin. We have examined structural and spectroscopic properties of wild-type rhodopsin (with 11-cis-9,13-di...

Potential Energy Surfaces

Adiabatic representation Representation in which the electronic wave functions are calculated for fixed (i.e., nonmoving) nuclei. Avoided intersection Case in which two potential energy surfaces come together but do not intersect. Conical intersection Case in which two potential energy surfaces intersect such that their separation decreases to zero linearly in the relevant nuclear coordinates. ...

Computational study of three dimensional potential energy surfaces in intermolecular hydrogen bonding of cis-urocanic acid

Reversible Photoisomerization of Spiropyran on the Surfaces of Au25 Nanoclusters.

Au25 nanoclusters functionalized with a spiropyran molecular switch are synthesized via a ligand-exchange reaction at low temperature. The resulting nanoclusters are characterized by optical and NMR spectroscopies as well as by mass spectrometry. Spiropyran bound to nanoclusters isomerizes in a reversible fashion when exposed to UV and visible light, and its properties are similar to those of f...

UV Excimer Laser Photoproducts from Absorbing and Transparent Surfaces Covered by Aluminum Alkyl Adsorbates

Neutral atomic and molecular species, generated upon the interaction of UV excimer laser light with Al-alkyl/substrate interfaces, are detected by single-shot dye laser mass spectroscopy. The molecules studied at 308, 248, and 193 nm are trimethylaluminum (TMA), triethylaluminum (TEA), and triisobutylaluminum (TIBA). The substrate is either n-type Si( 100) or Si02 (quartz). The major aluminum-c...