The reactions of polyfluorochalcones with o aminothiophenol in methanol in the presence of HCl afford polyfluorine substituted 2,3 dihydrobenzo[b] [1,5]thiazepines. In some cases, the cyclization is accompanied by fluorine substitution in the perfluorophenyl ring. Probably, the formation of thiazepines proceeds through the Michael thia adduct. The Zn salt of o amino thiophenol reacts with chalcones in DMF exclusively via fluorine substitution.

In this work the theoretical study of pulse string construction of holographic gratings in photopolymeric materials with light-induced optical attenuation has been carried out. The analytical model describing spatial-temporal transformation of holographic grating field during construction process is developed. The model has a view of recurrence relation and takes into consideration light-induced changing of optical attenuation and diffusion processes. The results of numerical simulation on the base of the model are presented and include analysis of record stage, self-amplification stage and whole pulse string construction. The behavior of spatial profile and diffraction characteristics of constructed gratings are estimated with the help ofnumerical simulation. Fitting experiment and theoretical data has been made.The researched photopolymer was made in Institute of Organic Chemistry of the Siberian Separation of a Russian Academy of Sciences (Novosibirsk).

No abstract

We demonstrate holographic recording in a new photopolymer system. The recording material is created by copolymerization of an optically inert monomer, methyl methacrylate, and a second monomer that is optically sensitive. On exposure of the recording material to light, a portion of the optically sensitive component detaches from the polymer matrix and causes hologram amplif ication through diffusion of the free molecules. We measured postrecording grating amplif ications as high as 170% by this process. The recorded holograms are persistent at room temperature under continuous illumination at the recording wavelength. 

Experimental results for the nonlinear optical properties of thin films of molecular J-aggregates of substituted pseudoisocyanine (PIC) are reported. These molecular aggregates were found to possess a giant third-order optical nonlinearity (jc 3 j % 10 À5 esu). Thin films of J-aggregates of PIC iodide with several different N-alkyl substituents were obtained to study the effect of disorder on the nonlinear optical properties. The spectral features of the nonlinear optical susceptibility are analyzed within a model that includes exciton±exciton interactions.

Nonlinear optical properties of one-dimensional organic molecular aggregates in nanometer films Markov, R.V.; Plekhanov, A.I.; Shelkovnikov, V.V.; Knoester, J. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractNanometer films of molecular J-aggregates of pseudoisocyanine (PIC) with various degrees of both static and dynamic disorder were prepared. The amount of static disorder was varied by modifying the local environment of the J-aggregates in the films, while the dynamic disorder was varied by changing the film temperature. Through these variations, the delocalization length N of the excitons was controlled, as could be monitored from the width of the exciton absorption del (3) line. This has allowed us to establish the scaling of the nonlinear optical susceptibility per aggregate molecule, x /N, with

No abstract

No abstract