Preparation, Characterization and Catalytic Properties of Polyaniline‐Supported Metal Complexes

Abstract

Polyaniline-supported Sc, In, Pd, Os and Re catalysts were prepared by using a simple protocol and the thus prepared catalysts were well characterized using FTIR, XPS, UV-Vis/DRS, TGA-DTA. All the catalysts were successfully employed in a wide range of organic transformations such as cyanation and allylation of carbonyl compound, Suzuki coupling of aryl halides and boronic acids, and, most importantly, in asymmetric dihydroxylation of olefins to afford optically active vicinal diols. All the catalysts were separated from the reaction mixture by simple filtration and reused with consistent activity for five cycles without noticeable leaching of metal from the support.

Palladium Nanoparticles Supported on Polyaniline Nanofibers as a Semi‐Heterogeneous Catalyst in Water

“…[1] When polyaniline (PANI) is used as support, it also functions as reducing agent and stabilizer. These advantages translate into easy and reproducible syntheses that make metal nanoparticles supported by PANI [2,3] promising candidates for organic catalysis. Palladium nanoparticles supported on polyaniline have been the subject of interest of several groups.…”

“…Palladium nanoparticles supported on polyaniline have been the subject of interest of several groups. [2,3] In general, these nanoparticles are prepared by adding a palladium(II) salt to an aqueous dispersion of PANI. [2] When interfacial polymerization is used for the synthesis of PANI, nanofibers are formed.…”

“…[2,3] In general, these nanoparticles are prepared by adding a palladium(II) salt to an aqueous dispersion of PANI. [2] When interfacial polymerization is used for the synthesis of PANI, nanofibers are formed. [4] The high surface area and porosity of the PANI nanofibers serve as an ideal environment to make metal/ polyaniline nanocomposites.…”

A mechanistic study of cross-coupling reactions catalyzed by palladium nanoparticles supported on polyaniline nanofibers

“…25,27 Our system is also advantageous because it does not need a phase transfer agent like tetrabutylammonium bromide to help with the hydrophobicity of aryl chlorides. 48,49 At the time of our initial report, we hypothesized that a dissolution and redeposition mechanism was operating. Over the past decade, there have been contradicting claims on the true type of catalysis that takes place with palladium nanoparticles.…”

“…We 47 and others 48,49 previously reported that palladium nanoparticles supported on PANI nanofibers work well for Suzuki coupling in water. In our case, the palladium nanoparticles showed a bimodal distribution with particles of 2 and 50 nm in diameter being present.…”