Multi-Stimuli-Responsive Luminescent Ruthenium(II) Complexes as a Selective Sensor for Cyanide Detection in Aqueous...

Area of Science:

• Coordination Chemistry
• Materials Science
• Luminescent Materials

Background:

• Developing functional materials with tunable properties is crucial for advanced applications.
• Stimuli-responsive materials offer dynamic control over material characteristics.
• Ruthenium complexes are known for their photophysical properties and potential in sensing.

Purpose of the Study:

• To synthesize and characterize novel luminescent ruthenium complexes with mixed terpyridine-bipyridine ligands.
• To investigate the multistimulus-responsive behavior of these complexes.
• To explore their potential for anion sensing.

Main Methods:

• Synthesis of ruthenium complexes [Ru(L)(4,4'-dmbpy)(pz)](ClO4)2 [1] and [Ru(L)(4,4'-dmbpy)(1Mepz)](ClO4)2 [2].
• Characterization using single-crystal X-ray diffraction and spectroscopic techniques.
• Evaluation of luminescence, optical, and redox properties under various stimuli (anionic guests, temperature, light).
• Anion sensing experiments, including Job's plot and density functional theory (DFT) analysis.

Main Results:

• Both complexes exhibit strong room-temperature luminescence.
• Multistimulus-responsive behavior was observed, with optical and redox properties being finely tuned.
• Complex 1 demonstrated selective cyanide ion (CN-) sensing in aqueous media down to 10^-6 M.
• Complex 2 did not exhibit anion-sensing properties due to the absence of an acidic -NH proton.

Conclusions:

• The synthesized ruthenium complexes display promising stimuli-responsive and luminescent characteristics.
• Complex 1 shows potential as a selective sensor for cyanide ions in aqueous solutions.
• The study highlights the importance of ligand design in tuning the properties of ruthenium complexes for sensing applications.