UNIGE document Scientific Article
previous document  unige:90268  next document
add to browser collection
Title

Physicochemical and Electronic Properties of Cationic [6]Helicenes: from Chemical and Electrochemical Stabilities to Far-Red (Polarized) Luminescence

Authors
Li, Haidong
Bouffier, Laurent
Sojic, Neso
show hidden authors show all authors [1 - 15]
Published in Chemistry - A European Journal. 2016, vol. 22, no. 51, p. 18394-18403
Abstract The physicochemical properties of cationic dioxa (1), azaoxa (2), and diaza (3) [6]helicenes demonstrate a much higher chemical stability of the diaza adduct 3 (pKR+=20.4, inline image =−0.72 V) compared to its azaoxa 2 (pKR+=15.2, inline image =−0.45 V) and dioxa 1 (pKR+=8.8, inline image =−0.12 V) analogues. The fluorescence of these cationic chromophores is established, and ranges from the orange to the far-red regions. From 1 to 3, a bathochromic shift of the lowest energy transitions (up to 614 nm in acetonitrile) and an enhancement of the fluorescence quantum yields and lifetimes (up to 31 % and 9.8 ns, respectively, at 658 nm) are observed. The triplet quantum yields and circularly polarized luminescence are also reported. Finally, fine tuning of the optical properties of the diaza [6]helicene core is achieved through selective and orthogonal post-functionalization reactions (12 examples, compounds 4–15). The electronic absorption is modulated from the orange to the far-red spectral range (560–731 nm), and fluorescence is observed from 591 to 755 nm with enhanced quantum efficiency up to 70 % (619 nm). The influence of the peripheral auxochrome substituents is rationalized by first-principles calculations.
Keywords Circularly polarized luminescenceDensity functional calculationsElectrochemistryFluorescenceHelicenes
Identifiers
Full text
Article (Published version) (3.5 MB) - document accessible for UNIGE members only Limited access to UNIGE
Corrigendum (393 Kb) - document accessible for UNIGE members only Limited access to UNIGE
Structures
Research groups Groupe Lacour
Groupe Vauthey
Citation
(ISO format)
BOSSON, Johann et al. Physicochemical and Electronic Properties of Cationic [6]Helicenes: from Chemical and Electrochemical Stabilities to Far-Red (Polarized) Luminescence. In: Chemistry - A European Journal, 2016, vol. 22, n° 51, p. 18394-18403. https://archive-ouverte.unige.ch/unige:90268

256 hits

6 downloads

Update

Deposited on : 2016-12-13

Export document
Format :
Citation style :