Design and Synthesis of Photofluorochromic Coordination Polymers Featuring Dual-Mode Output for Dynamic...

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Photofluorochromic compounds offer dual-mode output for high-security applications.
• Challenges exist in constructing these materials due to competing photoinduced electron transfer (PIET) and fluorescence processes.

Purpose of the Study:

• To design and synthesize novel photofluorochromic materials by extending ligand conjugation length.
• To explore the potential of these materials in anticounterfeiting technologies.

Main Methods:

• Synthesis of a ligand with extended conjugation: (HL)Cl = 1-((4'-carboxy-[1,1'-biphenyl]-4-yl)methyl)-[4,4'-bipyridin]-1-ium) chloride.
• Formation of two coordination polymers, [Cd(L)(HL1)]·DMF·2H2O (1) and [Zn2(L)(L2)(H2O)2]·2H2O (2), via thermal reactions with metal ions and ligands.
• Characterization of photochromic and luminescent properties.

Main Results:

• Successful synthesis of two novel coordination polymers with excellent photochromic and luminescent properties.
• Demonstrated excellent reversibility of photochromic processes over five cycles.
• Attributed excellent luminescence post-photochromism to promoted charge transfer from extended conjugation.

Conclusions:

• The developed photofluorochromic coordination polymers show significant potential for high-security anticounterfeiting applications.
• The dual-mode output (photochromism and luminescence) enhances security features for applications like banknote authentication.
• This work provides insights into developing advanced photofluorochromic coordination polymers.