Carving Out Pores in Redox-Active One-Dimensional Coordination Polymers

Area of Science:

• Materials Science
• Inorganic Chemistry
• Polymer Chemistry

Background:

• One-dimensional coordination polymers offer unique electronic and structural properties.
• The development of conductive and porous materials is crucial for various technological applications.
• Controlling the properties of coordination polymers through chemical modification is an active area of research.

Purpose of the Study:

• To synthesize a conductive, porous polymer from an insulating precursor.
• To investigate the conductivity and surface properties of the resulting material.
• To explore the influence of counteranions on the properties of the reduced polymer.

Main Methods:

• Chemical reduction of the insulating polymer [Cu(abpy)PF6]n to yield [Cu(abpy)]n.
• Measurement of electrical conductivity using pressed pellets.
• Determination of surface area using the Brunauer-Emmett-Teller (BET) method.
• Cyclic voltammetry to assess the reversibility of the reduction process.

Main Results:

• The reduction process yielded a conductive, porous polymer, [Cu(abpy)]n, with a conductivity of 0.093 S cm⁻¹.
• The BET surface area of [Cu(abpy)]n was found to be 56 m² g⁻¹ for pressed pellets and 90 m² g⁻¹ for fine powders.
• The reduction was quasi-reversible, indicating efficient charge transfer.
• Varying the counteranion (X) in [Cu(abpy)X]n allowed control over the BET surface area of the reduced polymer, with X=Br yielding 60 m² g⁻¹ and X=BArF yielding 200 m² g⁻¹.

Conclusions:

• The chemical reduction of [Cu(abpy)PF6]n provides a facile route to conductive and porous [Cu(abpy)]n.
• The conductivity and significant surface area of [Cu(abpy)]n suggest potential applications in areas requiring charge transport and high surface interactions.
• The ability to tune the surface area by modifying the counteranion highlights a versatile strategy for designing functional porous coordination polymers.