Reversible Electrochromic/Electrofluorochromic Dual Switching in Zn(II)-Based Metallo-Supramolecular Polymer Films.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Optoelectronics

Background:

• Multifunctional chromogenic materials with electrochromic/electrofluorochromic (EC/EFC) properties are crucial for advanced optoelectronic devices and smart windows.
• Developing novel materials with combined EC/EFC capabilities is an active area of research.

Purpose of the Study:

• To synthesize and characterize a novel Zn(II)-based metallo-supramolecular polymer (polyZn) with switchable EC/EFC properties.
• To investigate the potential of polyZn for applications in optoelectronics and bioimaging.

Main Methods:

• Synthesis of polyZn via 1:1 complexation of Zn(II) ions with a redox-active ditopic ligand (4,4'-[bis(2,2':6',2″-terpyridinyl)benzene]triphenylamine).
• Fabrication of thin films using spin-coating on an indium tin oxide/glass substrate.
• Electrochemical characterization to induce and observe EC/EFC transitions.
• Photoluminescence spectroscopy to analyze fluorescence properties.

Main Results:

• PolyZn exhibits excellent solubility and forms uniform thin films.
• The material displays a reversible ON/OFF switchable EFC behavior with prominent EC properties.
• Upon applying a +1.6 V bias, polyZn transitions from transparent yellow to green with near-infrared absorption, and its photoluminescence is quenched.
• The film recovers its original state and photoluminescence upon removal of the bias, demonstrating sustained ON/OFF EFC cycling.

Conclusions:

• The developed Zn(II)-based metallo-supramolecular polymer (polyZn) effectively integrates EC and EFC functionalities.
• PolyZn shows promise as a component in switchable optoelectronic devices and as a molecular probe for bioimaging.
• This work encourages the design of new materials combining metal-fluorescent cores with redox-active spacers for advanced applications.