skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Dual-site catalysis for sustainable polymers to replace current commodity polymers – carbonylative copolymerization of ethylene, ethylene oxide, and tetrahydrofuran
Title: Dual-site catalysis for sustainable polymers to replace current commodity polymers – carbonylative copolymerization of ethylene, ethylene oxide, and tetrahydrofuran
Zwitterionic Ni( ii )-catalyzed carbonylative copolymerization of ethylene and cyclic ethers for the synthesis of photolytically and hydrolytically degradable polymers is reported. The segmented tetrapolymer products are composed of polyketone segments from alternating enchainments of CO and ethylene and poly(ether- co -ester) segments from non-alternating enchainments of CO, ethylene oxide, and tetrahydrofuran. Plastic and elastic products can be obtained via the general synthetic platform with the appropriate choice of catalyst and polymerization conditions.  more » « less
Award ID(s):
1900430 1904397
PAR ID:
10279326
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
Chemical Communications
Volume:
56
Issue:
97
ISSN:
1359-7345
Page Range / eLocation ID:
15341 to 15344
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Advanced Energy Materials)
    Abstract The electrochemical carbon dioxide reduction reaction (CO2RR) is a promising approach for reducing atmospheric carbon dioxide (CO2) emissions, allowing harmful CO2to be converted into more valuable carbon‐based products. On one hand, single carbon (C1) products have been obtained with high efficiency and show great promise for industrial CO2capture. However, multi‐carbon (C2+) products possess high market value and have demonstrated significant promise as potential products for CO2RR. Due to CO2RR's multiple pathways with similar equilibrium potentials, the extended reaction mechanisms necessary to form C2+products continue to reduce the overall selectivity of CO2‐to‐C2+electroconversion. Meanwhile, CO2RR as a whole faces many challenges relating to system optimization, owing to an intolerance for low surface pH, systemic stability and utilization issues, and a competing side reaction in the form of the H2evolution reaction (HER). Ethylene (C2H4) remains incredibly valuable within the chemical industry; however, the current established method for producing ethylene (steam cracking) contributes to the emission of CO2into the atmosphere. Thus, strategies to significantly increase the efficiency of this technology are essential. This review will discuss the vital factors influencing CO2RR in forming C2H4products and summarize the recent advancements in ethylene electrosynthesis. 
    more » « less
  2. ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract A metal/ligand cooperative approach to the reduction of small molecules by metal silylene complexes (R2Si=M) is demonstrated, whereby silicon activates the incoming substrate and mediates net two‐electron transformations by one‐electron redox processes at two metal centers. An appropriately tuned cationic pincer cobalt(I) complex, featuring a central silylene donor, reacts with CO2to afford a bimetallic siloxane, featuring two CoIIcenters, with liberation of CO; reaction of the silylene complex with ethylene yields a similar bimetallic product with an ethylene bridge. Experimental and computational studies suggest a plausible mechanism proceeding by [2+2] cycloaddition to the silylene complex, which is quite sensitive to the steric environment. The CoII/CoIIproducts are reactive to oxidation and reduction. Taken together, these findings demonstrate a strategy for metal/ligand cooperative small‐molecule activation that is well‐suited to 3dmetals. 
    more » « less
  3. ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract Converting CO2into industrially useful products is an appealing strategy for utilization of an abundant chemical resource. Electrochemical CO2reduction (eCO2R) offers a pathway to convert CO2into CO and ethylene, using renewable electricity. These products can be efficiently copolymerized by organometallic catalysts to generate polyketones. However, the conditions for these reactions are very different, presenting the challenge of coupling microenvironments typically encountered for the transformation of CO2into highly complex but desirable multicarbon products. Herein, we present a system to produce polyketone plastics entirely derived from CO2and water, where both the CO and C2H4intermediates are produced by eCO2R. In this system, a combination of Cu and Ag gas diffusion electrodes is used to generate a gas mixture with nearly equal concentrations of CO and C2H4, and a recirculatory CO2reduction loop is used to reach concentrations of above 11% each, leading to a current‐to‐polymer efficiency of up to 51% and CO2utilization of 14%. 
    more » « less
  4. ; ; ; (, Organometallics)
    The coupling of carbon dioxide and ethylene to generate value added chemicals has been part of recent fundamental advances to improve sustainability in commercial chemical synthons. A formal zerovalent triphosphine ligated ruthenium complex, (tBuP(CH2CH2PEt2)2)Ru(κ-S-DMSO)(C2H4), was found to promote CO2 activation, affording products derived from both a 1:1 and 1:2 ethylene to CO2 coupling stoichiometry. The equimolecular coupling reaction selectively afforded a five-membered ruthenium lactone species, (tBuP(CH2CH2PEt2)2)Ru(κ-S-DMSO)(κ-C,κ-O-CH2CH2CO2), under low CO2 pressure. At higher CO2 pressure, the ruthenium lactone complex activated a second equivalent of CO2, yielding a dimeric methylmalonate ruthenium compound, [(tBuP(CH2CH2PEt2)2)Ru(μ2, κ1-O, κ2-O,O-O2CCHCH3CO2)]2. Both carbon dioxide activation products were characterized by X-ray diffraction. Preliminary mechanistic studies suggest that reversible β-H elimination is a key process in conversion between the two ruthenium carboxylate species. A rare formally zerovalent ruthenium coordination compound stabilized only by ethylene and DMSO ligands was also isolated and characterized. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Nature Communications)
    Abstract Direct implementation of metal-organic frameworks as the catalyst for CO 2 electroreduction has been challenging due to issues such as poor conductivity, stability, and limited > 2e − products. In this study, Au nanoneedles are impregnated into a cupric porphyrin-based metal-organic framework by exploiting ligand carboxylates as the Au 3+ -reducing agent, simultaneously cleaving the ligand-node linkage. Surprisingly, despite the lack of a coherent structure, the Au-inserted framework affords a superb ethylene selectivity up to 52.5% in Faradaic efficiency, ranking among the best for metal-organic frameworks reported in the literature. Through operando X-ray, infrared spectroscopies and density functional theory calculations, the enhanced ethylene selectivity is attributed to Au-activated nitrogen motifs in coordination with the Cu centers for C-C coupling at the metalloporphyrin sites. Furthermore, the Au-inserted catalyst demonstrates both improved structural and catalytic stability, ascribed to the altered charge conduction path that bypasses the incoherent framework. This study underlines the modulation of reticular metalloporphyrin structure by metal impregnation for steering the CO 2 reduction reaction pathway. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email