Visibly emissive and responsive extended 6-aza-uridines

Area of Science:

• Organic Chemistry
• Nucleoside Chemistry
• Photophysics

Background:

• 6-Aza-uridines are modified nucleosides with potential applications in medicinal chemistry and molecular probes.
• Tuning electronic properties of nucleoside analogs is crucial for developing new functional materials.

Purpose of the Study:

• To synthesize and characterize a series of extended 5-modified-6-aza-uridines.
• To investigate the impact of aryl ring conjugation on the photophysical properties of these nucleoside analogs.

Main Methods:

• Suzuki coupling reactions were employed to attach substituted aryl rings to a common brominated 6-aza-uridine precursor.
• UV-Vis absorption and fluorescence emission spectroscopy were used to determine photophysical properties.

Main Results:

• A family of extended 5-modified-6-aza-uridines was successfully synthesized.
• The extended conjugated systems demonstrated significant bathochromic shifts in absorption and emission spectra compared to parent nucleosides.
• Solvatochromic effects were observed, with varying emission maxima depending on the solvent polarity (e.g., dioxane and water).
• Derivative 1d showed absorption maxima around 375 nm and emission maxima at 486 nm (Φ = 0.74) in dioxane and 525 nm (Φ = 0.02) in water.

Conclusions:

• Extending the conjugation of 6-aza-uridines with aryl rings enhances push-pull interactions, leading to notable bathochromic shifts and solvatochromism.
• These findings contribute to the rational design of novel nucleoside derivatives with tunable optical properties for potential applications.