Structural assignment of fluorocyclobutenes by 19f nmr spectroscopy – comparison of calculated 19f nmr shielding constants with experimental 19f nmr shifts

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F18%3A43917617" target="_blank" >RIV/60461373:22310/18:43917617 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1002/ejoc.201801119" target="_blank" >http://dx.doi.org/10.1002/ejoc.201801119</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/ejoc.201801119" target="_blank" >10.1002/ejoc.201801119</a>

Result language

angličtina

Original language name

Structural assignment of fluorocyclobutenes by 19f nmr spectroscopy – comparison of calculated 19f nmr shielding constants with experimental 19f nmr shifts

Original language description

Although the optimized reduction of perfluorocyclobutene with LiAlH4 gave a quantitative yield of the target 3,3,4,4-tetrafluorocyclobut-1-ene, unoptimized reductions led to complex inseparable mixtures of fluorocyclobutenes. These mixtures showed highly complex19F NMR spectra, the assignment of which was quite tedious. Hence, we accomplished a series of19F NMR magnetic shielding computations. Suprisingly, various DFT approaches, including both traditional and advanced functionals, gave highly diverse results with poor correlations between the experimental and computed19F chemical shifts, and the individual fluorocyclobutenes could not be identified. In contrast, the Hartree–Fock (HF) method gave shielding values which, although bearing some systematic error, enabled the assignment of all observed structures. Even better results were obtained by using a specially tailored IGLO-III basis set. The method developed was successfully employed for the assignment of the19F NMR shifts of unknown fluorocyclobutenes. © 2018 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10401 - Organic chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

European Journal of Organic Chemistry

ISSN

1434-193X

e-ISSN

—

Volume of the periodical

Neuveden

Issue of the periodical within the volume

srpen

Country of publishing house

DE - GERMANY

Number of pages

3

Pages from-to

"3875–3877"

UT code for WoS article

000456391900002

EID of the result in the Scopus database

2-s2.0-85054742687