A facile high-yield synthetic route has been established for the synthesis of R-hydroxy methyl ketones. These intermediates are important precursors to the tricyanovinyldihydrofuran type of acceptor used in high µβ nonlinear optical chromophores. 3-Hydroxy-3-methyl-2-butanone is one of only three commercially available precursors of this type, limiting the chemist from making systematic studies of structure property relationships. This very general synthetic method allows a wide variety of R-hydroxy ketone structures to be easily made.Supporting Information Available: General experimental data: GC/MS analyses of compounds 1-12 and the HPLC analyses of compounds 14-23 (PDF). This material is available free of charge via the Internet at http://pubs.acs.org. CM011734T
We have successfully synthesized several new substituted thiophene-based electro-optic chromophores. All of these chromophores have structures similar to FTC but they incorporated our newly designed tricyanovinyldihydrofuran acceptors. Since these acceptors possess an anisotropic structure, all of the chromophores are very soluble in a wide range of organic solvents. Thermal study of these chromophores by TGA shows all of them are very stable in air. UV spectra indicate the chromophores have a large solvatochromic effect, implying very large molecular nonlinearities.
Four new isophorone and combined isophorone and thiophene bridged chromophores have been synthesized. All of these new high µβ chromophores possess our newly synthesized tricyanovinyldihydrofuran acceptors. Because of our unique acceptor design, all of our chromophores show high solubility in all organic solvents due to minimized chromophorechromophore electrostatic interactions. These chromophores have also been studied with respect to their solvatochromism and thermal behavior by TGA in air. Preliminary EO characterization of one of these chromophores in polycarbonate has demonstrated an extremely high r 33 of 70 pm/V at 1550 nm. We believe that this is the largest r 33 reported at this wavelength.
Hole mobilities of 4-diethylaminobenzaldehyde diphenylhydrazone (HDZ-F) doped poly(styrene) have been measured over a wide concentration range. The results have been described by a formalism based on disorder. The formalism is premised on the argument that charge transport occurs by hopping through a manifold of localized states that are distributed in energy and distance. The key parameter of the formalism is σ, the energy with of the hopping site manifold. For HDZ-F doped PS, σ is concentration-dependent. The maximum value is 0.121 eV and occurs at approximately 15% HDZ-F. The width decreases sharply for concentrations above and below. The concentration dependence is described by a model of dipolr disorder. The model is based on the assumption that the total widths are comprised of a dipolar component and a van der Waals component. The interpretation of the experimental results leads to the conclusion that the concentration dependence of the total width is largely determined by the van der Waals component.
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