Donor-and-acceptor substituted truxenes as multifunctional fluorescent probes

Area of Science:

• Organic Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Truxene derivatives offer a unique triangular scaffold for developing advanced functional materials.
• Charge-transfer compounds with donor (D) and acceptor (A) moieties are crucial for optical sensing applications.
• Solvatochromism and fluorescence ratiometry are key properties for developing chemical sensors.

Purpose of the Study:

• To synthesize novel dimesitylboryl acceptor and diphenylamino donor-substituted truxene derivatives.
• To investigate the solvatochromic properties of these compounds for probing solution polarity.
• To evaluate their potential as fluorescent probes for detecting fluoride ions.

Main Methods:

• Synthesis of truxene derivatives with specific donor and acceptor groups (A-pi-D2 or A2-pi-D).
• Spectroscopic analysis (UV-Vis absorption and fluorescence) in various aprotic and protic solvents.
• Investigation of spectral responses to varying fluoride ion concentrations.

Main Results:

• Synthesized D-or-A and D-and-A substituted truxene compounds, including BN2 and B2N.
• Observed large solvatochromism (420 nm to 580 nm) in BN2 and B2N, sensitive to solvent polarity.
• Demonstrated decreased solvatochromic shifts in protic solvents and sharp spectral responses to fluoride ions, enabling ratiometric fluorescence detection.

Conclusions:

• Truxene-based charge-transfer compounds (BN2 and B2N) are effective for sensing solution polarity and fluoride ions.
• The observed spectral phenomena are attributed to the strategic grafting of donor and acceptor moieties onto the truxene core.
• These compounds offer a promising platform for developing sensitive and selective fluorescent ratiometric probes.