English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In an effort to enhance the absorption and fluorescence of flavylium in the red and near-infrared (NIR) spectral region, we synthesized a 2′-hydroxyflavylium derivative (FLV-OH) with a rigid electron donating julolidine group attached to position 7 and examined its ground and excited states spectroscopy by absorption, fluorescence, ultrafast dynamics, and by density functional theory (DFT). The precursor compound without the hydroxyl group (FLV) was also synthesized and characterized in order to clarify the role of the intramolecular hydrogen bond on the spectroscopy of FLV-OH. The S1 ← S0 absorption peaks at 540 nm and extends to 620 nm, whereas the corresponding fluorescence has two peaks and extends to 900 nm. The ability of the flavylium moiety to undergo ring opening to form chalcone is observed in basic solution. The presence of the hydroxyl group in FLV-OH promotes the formation of a quinonoidal base which was not possible in FLV. Femtosecond fluorescence upconversion and transient absorption measurements reveal the solvation dynamics within the initial 1-2 ps after photexcitation, followed by molecular relaxation to the ground state. The latter was measured to be 505 ps in FLV-OH and 164 ps in FLV. The longer lifetime of FLV-OH in the excited state is correlated to the presence of a hydrogen bond (OH---O) that tends to stabilize the excited molecule. The current results indicate that FLV-OH has spectroscopic properties that make it suitable for many applications such as a potential light harvesting dye in solar cell

Steady-state spectroscopy and ultrafast dynamics of flavylium derivatives in the red and near-infrared spectral region