Dearomative Cycloadditions Utilizing an Organic Photosensitizer: An Alternative to Iridium Catalysis
ORGANIC LETTERS
Authors: Rolka, Alessa B.; Koenig, Burkhard
Abstract
A highly efficient, cheap, and organic alternative to the commonly used iridium photosensitizer (Ir[dF(CF3)ppy](2)(dtbpy))PF6([Ir-F]) is presented for visible-light energy transfer catalysis. The organic dye 2CzPN surpasses [Ir-F] in selectivity while at the same time being easily accessible in one step. The catalyst is recyclable and, due to its uncharged nature, soluble in nonpolar solvents such as toluene. Furthermore, the scope of molecular scaffolds that are compatible substrates for visible-light catalyzed dearomative cycloadditions is expanded.
Synthesis and characterization of Polyvinyl Alcohol-Polypyrrole- Silver nanocomposite polymer films with core-shell structure
INTERNATIONAL JOURNAL OF NANO DIMENSION
Authors: Nerkar, Dattatray; Rajwade, Madhav; Jaware, Suryakant; Jog, Milind
Abstract
The present paper describes the preparation and characterization of Polyvinyl Alcohol-Polypyrrole-Silver Nanocomposite (PVA-PPy-Ag NC) films. The prepared films were conducting, freestanding, flexible, and robust. Silver nanoparticles (Ag NPs) were synthesized from an aqueous solution of silver nitrate using trisodium citrate as a reductant. The casting solution for the films was prepared by in-situ chemical oxidative polymerization of pyrrole. This was done in the presence of Polyvinyl Alcohol and suspension of pre-synthesized silver nanoparticles. The absorption band at 424 nm in UV-Visible Spectroscopy of silver nanoparticles confirmed the formation of Ag nanoparticles. Scanning Electron Microscopy (SEM) studies revealed that spherical Ag NPs were produced with an average size of similar to 25 nm. The morphological analysis of the synthesized PVA-PPy-Ag nanocomposite films was carried out using Transmission Electron Microscopy (TEM). It was observed in the TEM images that Ag nanoparticles were well dispersed and conjugated in the PVA-PPy matrix. The structure of the produced films was studied by Fourier transform infrared (FTIR) Spectroscopy and X-Ray Diffraction (XRD). X-ray diffraction analysis exhibited the crystalline nature of the silver nanoparticles with a face-centered cubic (fcc) structure. The synthesized PVA-PPy-Ag nanocomposite films can be further utilized as potential material for the fabrication of gas sensors.
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