Synthesis and characterisation of ruthenium complexes containing a pendent catechol ring

Area of Science:

• Coordination Chemistry
• Organometallic Chemistry
• Photochemistry

Background:

• Ruthenium complexes with polypyridyl ligands are widely studied for their photophysical and electrochemical properties.
• Triazole-based ligands offer versatile coordination modes and tunable electronic characteristics.
• Understanding the interplay between ligand structure and complex properties is crucial for developing new functional materials.

Purpose of the Study:

• To synthesize and characterize novel ruthenium(II) complexes featuring functionalized triazole ligands (HL1 and HL2).
• To investigate the structural, electronic, acid-base, and photophysical properties of these new complexes.
• To explore the electrochemical behavior and potential proton transfer phenomena within the complexes.

Main Methods:

• Synthesis of ruthenium(II) complexes with bipyridine/phenanthroline and triazole ligands.
• Characterization using X-ray crystallography, NMR, UV/Vis, and emission spectroscopy.
• Electrochemical and spectroelectrochemical studies, including ZINDO calculations and partial deuteriation techniques.

Main Results:

• Successful synthesis and full characterization of [Ru(bipy)2L1]+, [Ru(phen)2L1]+, [Ru(bipy)2L2]+, and related species.
• Detailed structural and spectroscopic data revealing the coordination modes and electronic transitions.
• Evidence of proton transfer between the catechol and triazole moieties in the [Ru(bipy)2(L2)]+ complex upon ligand oxidation.

Conclusions:

• The synthesized ruthenium complexes demonstrate tunable electronic and photophysical properties influenced by the triazole ligand structure.
• The study highlights the potential for proton-coupled electron transfer processes in such systems.
• These findings contribute to the design of novel ruthenium-based functional materials with tailored electrochemical and photochemical responses.