Diamond and diamond-like carbon from a preceramic polymer

The synthesis of poly(hydridocarbyne), one of a class of carbon-based random network polymers and a structural isomer of polyacetlyene, is reported. The network backbone of this polymer is primarily composed of tetrahedrally hybridized carbon atoms, each bearing one hydride substituent and linked via three carbon-carbon single bonds into a three-dimensional random network of fused rings. This atomic-level carbon network backbone confers unusual properties on the polymer, including facile thermal decomposition to form diamond or diamond-like carbon high-quality films at atmospheric pressure, by direct deposition or by chemical vapor deposition (CVD), without the use of hydrogen or any other reagent.     

Copper(II) ion-sensing mechanism of oligo-phenylene vinylene derivatives: syntheses and theoretical calculations

Oligo-phenylene vinylene (oligo-PV) with two picolinamide side-groups and six methoxy end-groups was synthesized in order to be a fluorescent sensing molecule. Various metal ion solutions (1.5×10^?4 M) were added to the 1.5×10^?6 M acetonitrile solution of the fluorescent molecule. The fluorescent emission spectra showed that, at about the same concentration (1.5×10^?4 M), only Cu(II) ion can quench the fluorescent emission of the picolinamide-PV solution. Possible metal ion-sensing mechanisms could be either the binding at picolinamide side-groups or methoxy end-groups, or interchain-stacking driven by the metal ions. Hence, oligo-PVs with six methoxy end-groups but without substituted side-groups, and another oligo-PV with six methoxy end-groups and two ethoxy side-groups were synthesized for comparison. These molecules turned out to be inactive to any metal ion solutions. Moreover, quantum calculation was used to confirm the result. Binding energy and conformation were calculated and simulated. It could be concluded that nitrogen and oxygen atoms of the picolinamide group and one oxygen atom from the methoxy group are involved in the metal ion-binding process.     

Amino-Substituted para-Phenylenevinylenes (PPVs) as Platforms for Fluorescent Sensing Materials

Summary: Soluble para-phenylenevinylenes (PPVs) with amino side groups and different spacers have been synthesized. Photophysical properties showed that these compounds emitted light in blue region when dissolved in methanol. They have been designed in order to be platforms for attaching different functional groups to the amino units. Molecule 5 was a model compound which showed a quantum efficiency of 52% in methanol. Different spacers were added to the model compound to yield molecules 6 and 7 . The preliminary experiment showed that molecule 5 can interact with various metal ions in solution phase. The interaction was observed by the changes of fluorescent emission intensity of the molecule. This molecule will be further functionalized to be more specific in binding certain metal ions.