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Small changes - huge influences : NMR chemical shifts of Ni(II) complexes with polar substrates

Small changes - huge influences : NMR chemical shifts of Ni(II) complexes with polar substrates

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Prüfsumme: MD5:1620790a3ee3210517d4624dc434aff0

FRANK, Andrea, Andreas BERKEFELD, Matthias DREXLER, Heiko MÖLLER, Thomas EXNER, 2013. Small changes - huge influences : NMR chemical shifts of Ni(II) complexes with polar substrates. In: International Journal of Quantum Chemistry. 113(13), pp. 1787-1793. ISSN 0020-7608. eISSN 1097-461X. Available under: doi: 10.1002/qua.24401

@article{Frank2013Small-24361, title={Small changes - huge influences : NMR chemical shifts of Ni(II) complexes with polar substrates}, year={2013}, doi={10.1002/qua.24401}, number={13}, volume={113}, issn={0020-7608}, journal={International Journal of Quantum Chemistry}, pages={1787--1793}, author={Frank, Andrea and Berkefeld, Andreas and Drexler, Matthias and Möller, Heiko and Exner, Thomas} }

Exner, Thomas Neutral Ni(II) complexes have been shown to be highly valuable as robust and versatile catalysts in olefin polymerization. But they show reduced reactivity when the polar monomers methyl acrylate and vinyl acetate are incorporated. To get further insight into this behavior, NMR chemical shift calculations were performed on the system [(N,O) Ni (H) (PMe3)] 1 (N,O = κ<sup>2</sup>-N,O-{2,6-(3,5-(F3C)2C6H3)2C6H3) - N = C(H)-3,5-I2-2-O-C6H2}). The chemical shifts show reasonable agreement with experiment but are also extremely influenced by geometrical features of the complex as well as the inserted substrate. The first prominent feature, the low-field shift of the Ccarbonyl in the incorporated monomer, can only be reproduced when it is in close proximity to the Ni and in this way hinders the attack of a new monomer. Second, the almost 100 ppm difference in the chemical shift of the carbon of the two substrates directly bound to Ni can be reasoned by the different directionality of polarization as disclosed by natural bond orbital (NBO) analysis. 2014-04-30T22:25:05Z eng deposit-license Berkefeld, Andreas Exner, Thomas Möller, Heiko 2013 Frank, Andrea Drexler, Matthias Drexler, Matthias International Journal of Quantum Chemistry ; 113 (2013), 13. - S. 1787-1793 Frank, Andrea 2013-09-11T09:12:54Z Möller, Heiko Small changes - huge influences : NMR chemical shifts of Ni(II) complexes with polar substrates Berkefeld, Andreas

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

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