Molecules 2013, 18(8), 9010-9020; doi:10.3390/molecules18089010
Article

Ab Initio Calculations of Possible γ-Gauche Effects in the 13C-NMR for Methine and Carbonyl Carbons in Precise Polyethylene Acrylic Acid Copolymers

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Received: 23 June 2013; in revised form: 19 July 2013 / Accepted: 23 July 2013 / Published: 29 July 2013
(This article belongs to the Special Issue Computational Chemistry)
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Abstract: The impacts of local polymer chain conformations on the methine and carbonyl 13C-NMR chemical shifts for polyethylene acrylic acid p(E-AA) copolymers were predicted using ab initio methods. Using small molecular cluster models, the magnitude and sign of the γ-gauche torsional angle effect, along with the impact of local tetrahedral structure distortions near the carbonyl group, on the 13C-NMR chemical shifts were determined. These 13C-NMR chemical shift variations were compared to the experimental trends observed for precise p(E-AA) copolymers as a function acid group spacing and degree of zinc-neutralization in the corresponding p(E-AA) ionomers. These ab initio calculations address the future ability of 13C-NMR chemical shift variations to provide information about the local chain conformations in p(E-AA) copolymer materials.
Keywords: ab initio; 13C-NMR; chemical shift; trans-gauche; γ-gauche; methine; carbonyl
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MDPI and ACS Style

Alam, T.M. Ab Initio Calculations of Possible γ-Gauche Effects in the 13C-NMR for Methine and Carbonyl Carbons in Precise Polyethylene Acrylic Acid Copolymers. Molecules 2013, 18, 9010-9020.

AMA Style

Alam TM. Ab Initio Calculations of Possible γ-Gauche Effects in the 13C-NMR for Methine and Carbonyl Carbons in Precise Polyethylene Acrylic Acid Copolymers. Molecules. 2013; 18(8):9010-9020.

Chicago/Turabian Style

Alam, Todd M. 2013. "Ab Initio Calculations of Possible γ-Gauche Effects in the 13C-NMR for Methine and Carbonyl Carbons in Precise Polyethylene Acrylic Acid Copolymers." Molecules 18, no. 8: 9010-9020.


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