Diphenylamino-Modified Neutral Pt(II) Complexes: Their Aggregation-Induced Phosphorescent Emission and Picric...

Area of Science:

• Coordination Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Platinum(II) complexes are investigated for their photophysical properties.
• Aggregation-induced emission (AIE) and aggregation-induced phosphorescent emission (AIPE) are crucial phenomena in materials science.
• Developing sensitive sensors for explosives like picric acid (PA) is of significant importance.

Purpose of the Study:

• To synthesize and characterize novel neutral Pt(II) complexes with diphenylamino-modified 2-phenylpyridine ligands.
• To investigate the aggregation-induced phosphorescent emission (AIPE) properties of these complexes.
• To evaluate the potential of these AIPE-active complexes as sensors for picric acid (PA) detection.

Main Methods:

• Synthesis of three neutral Pt(II) complexes featuring cyclometalated diphenylamino-modified 2-phenylpyridine ligands and acetylacetone ancillary ligands.
• Structural characterization including X-ray crystallography to understand intermolecular interactions (Pt···Pt, hydrogen bonds).
• Photophysical studies in THF/H2O mixtures to confirm AIPE properties and assess sensing capabilities for PA via luminescence quenching.

Main Results:

• Three neutral Pt(II) complexes (1-3) were successfully synthesized and characterized.
• The complexes exhibit AIPE properties, influenced by Pt···Pt interactions and hydrogen bonds observed in crystal structures.
• The complexes demonstrated effective sensing of picric acid (PA) in aqueous media with a low limit of detection (70 nM), attributed to photo-induced electron transfer.

Conclusions:

• Novel Pt(II) complexes with AIPE characteristics have been developed.
• These complexes serve as effective fluorescent sensors for picric acid detection in aqueous environments.
• The findings contribute to the development of advanced luminescent materials for environmental sensing applications.