We have recently developed a technique that has great potential in producing proteins with photo-control of conformation and consequently activity (J. R. Kumita, O. S. Smart and G. A. Woolley, Proc. Natl. Acad. Sci. U. S. A., 2000, 97, 3803-3808). The method is based on incorporating two cysteine residues into the sequence of a polypeptide. An azobenzene derivative is subsequently used to produ...

We report a novel way to modulate the elastic modulus of azobenzene containing liquid crystal networks (LCNs) by exposure to light. The elastic modulus can cycle between different levels by controlling the illumination conditions. Exposing the polymer network to UV light near the trans absorption band of azobenzene gives a small reduction of the glass transition temperature thereby lowering the...

In this article are described dendritic structures containing photoactive groups at the surface or in the core. The observed supramolecular effects can be attributed to the nature of the photoactive group and their location in the dendritic architecture. The peripheric azobenzene groups in these dendrimeric compounds can be regarded as single residues that retain the spectroscopic and photochem...

The optical switching of coupled plasmons of silver nanoparticles derivatised with a photoisomerisable azobenzene ligand is presented. It is shown that nanoparticle clusters, linked with an azobenzene dithiol molecule, display switchable optical properties. The photoisomerisation of the linker molecule was used to vary the separation between nanoparticles, which was monitored by changes in the ...

Azobenzene derivatives are a unique class of photo-switch molecules with promising potential for nanoscale optical applications. We have studied the self-assembly and photo-induced mechanical switching azobenzene on Au(111) at single-molecule level by using scanning tunneling microscope (STM). 4,4′-Dibromo-azobenzene (Br-AB) assembled into two types well-ordered structures surfaces in trans-iso...

In order to allow spatial and temporal control of carbohydrate-specific bacterial adhesion, it has become our goal to synthesise azobenzene mannosides as photoswitchable inhibitors of type 1 fimbriae-mediated adhesion of E. coli. An azobenzene mannobioside 2 was prepared and its photochromic properties were investigated. The E→Z isomerisation was found to be highly effective, yielding a long-li...

A self-assembled supramolecular platform has been designed for reversibly controlling the concentration of a compound in solution, via a photochemical reaction. The system utilizes metal-ligand interactions between a Zn-porphyrin dimer and a pyridine-appended dithienylethene (DTE) photoswitch. In addition to reversible compound release, the spectral properties of the release scaffold provide a ...

In this study, two hydrazine derivatives, azobenzene and hydrazobenzene, were compressed in a diamond anvil cell at room temperature up to 28 GPa followed by decompression. In situ Raman spectroscopy was employed to monitor the pressure-induced structural evolutions. Azobenzene was found to undergo a phase transition at ~10 GPa. Further compression to 18 GPa resulted in an irreversible breakdow...

Following on from our recent enforced geometry optimization (EGO) investigation of isomerization in cis-stilbene (J Comput Chem, in press) we report the discovery of two interesting new, symmetrical "fused sandwich" isomers of both cis-stilbene and the related cis-azobenzene. The isomers were obtained by applying external forces to pairs of carbon atoms from each of the benzene rings in cis-sti...

Complex light-matter interactions in azobenzene polymers have limited our understanding of how photoisomerization induces deformation as a function of the underlying polymer network and form of the light excitation. A unified modeling framework is formulated to advance the understanding of surface deformation and bulk deformation of polymer films that are controlled by linear or circularly pola...