Topochemical photocycloaddition in two-dimensional lead-halide coordination polymers with tunable phosphorescence

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photochemistry

Background:

• Topochemical transformation preserves structural motifs, enabling new material synthesis.
• Single-crystal-to-single-crystal (SCSC) solid-state conversion offers precise structural control.
• Coordination polymers are versatile platforms for designing functional materials.

Purpose of the Study:

• To explore SCSC [2 + 2] photocycloaddition in 2D lead-halide coordination polymers.
• To investigate the influence of ligand and halide variations on photocycloaddition rates.
• To establish structure-property relationships during photo-transformation and explore post-synthetic modification.

Main Methods:

• Synthesis of diverse 2D lead-halide coordination polymers with bipyridyl ethylene (bpe) ligands.
• Characterization of structural changes during SCSC [2 + 2] photocycloaddition using X-ray diffraction.
• Analysis of optical absorption and emission properties of parent and photo-transformed materials.

Main Results:

• Achieved quantitative SCSC [2 + 2] photocycloaddition in a series of 2D lead-halide coordination polymers.
• Demonstrated systematic modulation of photocycloaddition rates by altering halide and bpe ligands.
• Observed significant changes in optical absorption and emission properties post-phototransformation due to cyclobutane linkage formation.

Conclusions:

• 2D lead-halide coordination polymers are effective platforms for SCSC photocycloaddition.
• Ligand and halide choice critically influences the dynamic [2 + 2] photocycloaddition process.
• Post-synthetic modification offers a viable route to tailor the properties of these photo-transformed materials.