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Title: Density Functional Theory Study of Spirodienone Stereoisomers in Lignin

Abstract

The spirodienone structure in lignin is a relatively recent discovery, and it has been found to occur in lignin of various plant species at concentrations of ~3%, which is sufficiently high to be important for better understanding of its properties and reactivity. The cyclic structure, with a ..beta..-1 bond, has been proposed to be a precursor for acyclic ..beta..-1 linkages in lignin. Previous analytical work has revealed the presence, but not the absolute configuration, of two stereoisomeric forms of spirodienone. The objective of the current work was to determine if there are thermodynamic differences that could help identify the experimentally observed stereoisomers. Results from density functional theory calculations reveal the presence of clusters of stereoisomers with varying stability that may be of use in narrowing the list of possible structures. Furthermore, the bond dissociation enthalpy of the cyclic ring exhibited a particularly high value for the C-O cleavage reaction relative to more conventional ether bonds in lignin, perhaps due to limited electron delocalization possibilities.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [2];  [2]
  1. USDA Forest Service, Auburn, AL (United States). Southern Research Station
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1378887
Report Number(s):
NREL/JA-5100-69117
Journal ID: ISSN 2168-0485
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Sustainable Chemistry & Engineering
Additional Journal Information:
Journal Volume: 5; Journal Issue: 8; Journal ID: ISSN 2168-0485
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; bond dissociation energy; density functional theory; lignin; spirodienone; stereoisomerism

Citation Formats

Elder, Thomas, Berstis, Laura, Beckham, Gregg T., and Crowley, Michael F. Density Functional Theory Study of Spirodienone Stereoisomers in Lignin. United States: N. p., 2017. Web. doi:10.1021/acssuschemeng.7b01373.
Elder, Thomas, Berstis, Laura, Beckham, Gregg T., & Crowley, Michael F. Density Functional Theory Study of Spirodienone Stereoisomers in Lignin. United States. doi:10.1021/acssuschemeng.7b01373.
Elder, Thomas, Berstis, Laura, Beckham, Gregg T., and Crowley, Michael F. 2017. "Density Functional Theory Study of Spirodienone Stereoisomers in Lignin". United States. doi:10.1021/acssuschemeng.7b01373.
@article{osti_1378887,
title = {Density Functional Theory Study of Spirodienone Stereoisomers in Lignin},
author = {Elder, Thomas and Berstis, Laura and Beckham, Gregg T. and Crowley, Michael F.},
abstractNote = {The spirodienone structure in lignin is a relatively recent discovery, and it has been found to occur in lignin of various plant species at concentrations of ~3%, which is sufficiently high to be important for better understanding of its properties and reactivity. The cyclic structure, with a ..beta..-1 bond, has been proposed to be a precursor for acyclic ..beta..-1 linkages in lignin. Previous analytical work has revealed the presence, but not the absolute configuration, of two stereoisomeric forms of spirodienone. The objective of the current work was to determine if there are thermodynamic differences that could help identify the experimentally observed stereoisomers. Results from density functional theory calculations reveal the presence of clusters of stereoisomers with varying stability that may be of use in narrowing the list of possible structures. Furthermore, the bond dissociation enthalpy of the cyclic ring exhibited a particularly high value for the C-O cleavage reaction relative to more conventional ether bonds in lignin, perhaps due to limited electron delocalization possibilities.},
doi = {10.1021/acssuschemeng.7b01373},
journal = {ACS Sustainable Chemistry & Engineering},
number = 8,
volume = 5,
place = {United States},
year = 2017,
month = 6
}

Journal Article:
Free Publicly Available Full Text
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