Preparation and Physicochemical Properties of [6]Helicenes Fluorinated at Terminal Rings

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985858%3A_____%2F19%3A00501626" target="_blank" >RIV/67985858:_____/19:00501626 - isvavai.cz</a>
Alternative codes found
RIV/00216224:14310/19:00109274 RIV/00216208:11310/19:10393767 RIV/61989592:15110/19:73594111
Result on the web
<a href="https://pubs.acs.org/doi/pdf/10.1021/acs.joc.8b02870" target="_blank" >https://pubs.acs.org/doi/pdf/10.1021/acs.joc.8b02870</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.joc.8b02870" target="_blank" >10.1021/acs.joc.8b02870</a>

Result language
angličtina
Original language name
Preparation and Physicochemical Properties of [6]Helicenes Fluorinated at Terminal Rings
Original language description
The first racemization-stable helicene derivatives fluorinated at terminal rings, 1,2,3,4-tetrafluoro[6]helicene (6) and 1,2,3,4,13,14,15,16-octafluoro[6]helicene (15), were synthesized via the Wittig reaction followed by oxidative photocyclization in an overall yield of 41% of 6 and 76% of 15. The changed electronic structure in fluorinated helicenes was reflected in a slight shift of UV−vis absorption, fluorescence excitation, and emission spectra maxima when compared to unsubstituted [6]helicene. Cyclic voltammetry revealed a moderate decrease in the HOMO−LUMO gap with increasing fluorination. The specific rotation of tetrafluoro[6]helicene 6 enantiomers was found to be approximately 25% lower than that of unsubstituted [6]helicene. The theoretical study of the racemization barrier suggested a shift toward higher energy with increasing fluorination. The increasing fluorination also significantly affected the intermolecular interactions in the crystal lattice. The observed CH···F interactions led to the formation of 1D-molecular chains in the crystal structures of both fluorinated helicenes.
Czech name
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Czech description
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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

Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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