The photoisomerization of the pseudo-geminal tetraene 11 furnishes the cyclooctadiene derivatives 13 and 15 with a completely new type of molecular bridge for a [2.2]paracyclophane which promise many interesting novel applications; the same is true for the photoisomerization of 22 to 23 and 24. The structures of these new hydrocarbons were established by X-ray crystallography and spectroscopic ...

A direct observation of the photochemical switching between colloidal crystals with different lattice constants in a liquid-crystal (LC) emulsion is reported. Glycerol droplets introduced in a nematic liquid crystal form two-dimensional hexagonal colloidal crystal at the nematic-air interface with a lattice constant depending on the surface tension sigmaLCA. We dope an azobenzene derivative int...

We present a stochastic model for the kinetics of photoinduced anisotropy in a sample of molecular chromophores that may undergo photoisomerization. It is assumed that the chromophores do not interact among them, but are embedded in a medium that slows down the rotational diffusion. The model makes use of data about the photoinduced reorientation of the single chromophore, its photoisomerizatio...

in the present study, theoretical chemical reactivates photo isomerization in cis-retinal as a natural photo switch in vision. dft hybrid functional, b3lyp and, post-hf method, were the theoretical methods applied utilizing g09 software. 6-31g+ (d,p) basis set employed for structural optimizations, and single point computations performed using b3lyp/6-31g+(d,p). the isomers cis molecule retinal...

The photoisomerization mechanism of the neutral form of the photoactive yellow protein (PYP) chromophore is investigated using ab initio quantum chemistry and first-principles nonadiabatic molecular dynamics (ab initio multiple spawning or AIMS). We identify the nature of the two lowest-lying excited states, characterize the short-time behavior of molecules excited directly to S2, and explain t...

Self-assembled monolayers (SAMs) containing azobenzene moieties are very attractive for a wide range of applications, including molecular electronics and photonics, bio-interface engineering and sensoring. However, very little is known about the aggregation and photoswitching behavior that azobenzene units undergo during the SAM formation process. Here, we demonstrate that the formation of thio...

A thorough study on the (E) to (Z) photoisomerization of ferulic acid derivatives (esters, amides all types, and ketones) was carried out. At photostationary state, only aliphatic or benzylic tertiary reach a nearly complete conversion isomers into ones, whereas for esters, primary secondary aromatic mixtures (Z)/(E) ranging from 7 : 93 72 28 are observed. Ketones show rather limited photoisome...