Structural Assignment of Fluorocyclobutenes by F-19 NMR Spectroscopy - Comparison of Calculated F-19 NMR Shielding Constants with Experimental F-19 NMR Shifts
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F18%3A43917614" target="_blank" >RIV/60461373:22310/18:43917614 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1002/ejoc.201800482" target="_blank" >http://dx.doi.org/10.1002/ejoc.201800482</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/ejoc.201800482" target="_blank" >10.1002/ejoc.201800482</a>
Alternative languages
Result language
angličtina
Original language name
Structural Assignment of Fluorocyclobutenes by F-19 NMR Spectroscopy - Comparison of Calculated F-19 NMR Shielding Constants with Experimental F-19 NMR Shifts
Original language description
While optimized reduction of perfluorocyclobutene with LiAlH4 gave quantitative yield of the target 3,3,4,4-tetrafluorocyclobut-1-ene, unoptimized reductions led to complex unseparable mixtures of fluorocyclobutenes. These mixtures showed highly complex 19F NMR spectra, the assignment of which proved to be quite tedious. We hence accomplished a series of single reference computations of 19F NMR magnetic shielding of the corresponding fluorine atoms. Suprisingly, various DFT approaches, including both traditional and advanced functionals, gave highly diverse results with poor correlation of experimental and computed 19F chemical shifts, from which individual fluorocyclobutenes could not be identified. Contrary to that, DLPNO-CCSD method, developed recently as a part of ORCA computational package, gave the shielding values which, although bearing some systematic error, enabled to assign all structures observed. Even slightly better values of the magnetic shielding were obtained by simple HF method using specially tailored IGLO-III basis set. The method developed was successfully employed for assigning the 19F NMR shifts to yet unknown fluorocyclobutenes.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - 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
Result continuities
Project
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Continuities
S - Specificky vyzkum na vysokych skolach
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Journal of Organic Chemistry
ISSN
1434-193X
e-ISSN
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Volume of the periodical
Neuveden
Issue of the periodical within the volume
srpen
Country of publishing house
DE - GERMANY
Number of pages
8
Pages from-to
"3867–3874"
UT code for WoS article
000456391900001
EID of the result in the Scopus database
2-s2.0-85054880178