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

Kód výsledku v IS VaVaI

RIV/67985858:_____/19:00501626 - isvavai.cz

Nalezeny alternativní kódy

RIV/00216224:14310/19:00109274 RIV/00216208:11310/19:10393767 RIV/61989592:15110/19:73594111

Výsledek na webu

https://pubs.acs.org/doi/pdf/10.1021/acs.joc.8b02870

DOI - Digital Object Identifier

10.1021/acs.joc.8b02870

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10401 - Organic chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Journal of Organic Chemistry

ISSN

0022-3263

e-ISSN

—

Svazek periodika

84

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

1980-1993

Kód UT WoS článku

000459367100031

EID výsledku v databázi Scopus

2-s2.0-85061525000