|
Energy Materials : Materials Science and Engineering for Energy Systems
Number of Followers: 19  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1748-9237 - ISSN (Online) 1748-9245 Published by Taylor and Francis  [2652 journals]
|
- Trisubstituted Triptycenes: Toward the Preparation of Three-Dimensional
Dendrimers-
Free pre-print version: Loading...
Authors: Alfredo Mellace; James E. Hanson
Pages: 1 - 5
Abstract: A synthesis of benzyl trisubstituted triptycenes is described. These triptycenes are precursors for producing a first generation (G1) poly(triptycylether) dendrimer, a derivative of known poly(arylether) dendrimers. The molecule necessary for the further elaboration into the eventual dendrimer is a carboxylic acid ester triptycene terminated with two ether substituents on another ring; the zero generation (G0). The synthesis begins with formation of the Diels-Alder adduct of benzoquinone and methyl 2-anthroate. This adduct is aromatized under basic conditions and the resulting anion trapped with a benzyl halide as an electrophile to form the trisubstituted triptycene. Access to the trisubstituted system is obtained through a highly improved, efficient and chromatography free preparation of anthracene derivatives, mainly methyl 2-anthroate.
PubDate: 2021-05-27
DOI: 10.12691/wjoc-9-1-1
Issue No: Vol. 9, No. 1 (2021)
-
- Qualitative and Quantitative Analyses of Synthesized Short-Chain Fatty
Acid Phenyl Esters Using Fourier-Transform Infrared Spectroscopy-
Free pre-print version: Loading...
Authors: Ronald P. D’Amelia; Masashi W. Kimura, Marie-Claire Villon
Pages: 6 - 17
Abstract: Fourier-transform infrared spectroscopy (FT-IR) is a widely used technique to qualitatively determine the molecular structure of organic compounds; however, using quantitative FT-IR (qFT-IR) for the compositional analyses of mixtures is less common. To reinforce instrumental use in undergraduate laboratories, we have devised a multipart experiment that not only combines the qualitative and quantitative aspects of FT-IR but also exposes students to computational and synthetic organic chemistry. The objectives of this experiment are to synthesize a series of phenyl esters (PhEs) of various molecular weights; use qualitative FT-IR to characterize and compare the synthesized products with standards, databases, and with theoretical spectra computed using the cost-efficient B97-3c functional; and determine the weight percent (wt. %) composition of a binary mixture. We report on the methodologies used to synthesize and purify four PhEs; characterize them using FT-IR, conduct theoretical calculations and compare their FT-IR spectra with experimental ones; and determine the wt. % composition of phenyl acetate (PhAc), phenyl propionate (PhPr), phenyl butyrate (PhBu), and phenyl hexanoate (PhHex) in binary mixtures ranging from 0% to 100%. The results show a strong, linear correlation of gravimetrically calculated wt. % composition of a selected compound in a binary mixture using qFT-IR. This experiment demonstrates the applicability of qFT-IR as an educational tool for the undergraduate chemical laboratory and combines four different branches of chemistry: computational, instrumental, organic, and analytical.
PubDate: 2021-07-08
DOI: 10.12691/wjoc-9-1-2
Issue No: Vol. 9, No. 1 (2021)
-
- Carboxymethylcellulose-supported Palladium Nanoparticles Formed in situ
for Suzuki-Miyaura Coupling Reaction-
Free pre-print version: Loading...
Authors: Xiaojian Liao; Yuemin Zhou, Fu Tang, Xia Lin, Yiqun Li
Pages: 18 - 28
Abstract: A green experiment is described here for direct fabrication of carboxymethylcellulose-supported palladium nanoparticles (PdNPs@CMC) in situ through a simple self-assemble and self-reduction process between carboxymethylcellulose (CMC-Na) and PdCl2 solution. The PdNPs@CMC was well characterized by ICP, UV-Vis, XPS, FTIR, SEM, and TEM techniques. The in situ synthesized PdNPs@CMC was proved to be an efficient catalyst for Suzuki-Miyaura coupling reaction under mild aerobic conditions. The superior catalytic performance of PdNPs@CMC is attributed to the coordination with carboxyl groups (−COO−) and free hydroxyl groups (−OH) as well as polymeric capping effect of CMC. Moreover, the catalyst showed no significant loss of its activity at least three consecutive cycles. This laboratory class is involved in the preparation and characterization of PdNPs@CMC as well as its catalytic application in Suzuki−Miyaura cross coupling reaction under green conditions. This laboratory class is suggested to divide into two parts. The first part includes the fabrication of catalyst in situ through a self-assemble and self-reduction of Pd(II) with CMC−Na, and characterization of the as-prepared catalyst using various techniques. The second part employs the resulting catalyst to perform a microscale Suzuki-Miyaura reaction, recycling of catalyst, and characterization of the product. By design, this comprehensive experiment set up for the third-year undergraduate, and aim to make students comprehend the concept of ion-exchange reaction, reduction reaction, carbon-carbon coupling reaction, supported catalysts, nanoparticles, and green chemistry as well as train the fundamental operation capability of students, and improve their experimental skills.
PubDate: 2021-09-09
DOI: 10.12691/wjoc-9-1-3
Issue No: Vol. 9, No. 1 (2021)
-
