Nanoscale layer-separated zincophosphate framework enabled by dual-mode aromatic pillar engineering for selective...

Area of Science:

• Materials Science
• Crystallography
• Supramolecular Chemistry

Background:

• Integrating bulky organic ligands into metal phosphate frameworks is challenging due to crystal growth issues.
• Limited structural information hinders the development of advanced functional materials.

Purpose of the Study:

• To synthesize a stable three-dimensional zincophosphate framework with a large π-conjugated organic ligand.
• To investigate the structural, thermal, and chemical properties of the new framework.
• To explore its potential for luminescent sensing applications.

Main Methods:

• Single-crystal X-ray diffraction (SCXD) for structural elucidation.
• Incorporation of 4,4'-di(4-pyridyl)biphenyl (DPBP) ligand into a zincophosphate scaffold.
• Luminescence spectroscopy for sensing studies.

Main Results:

• Successfully synthesized a 3D zincophosphate framework with nanoscale interlayer separation (>20 Å) using the DPBP ligand.
• DPBP ligand adopted dual coordination modes (bidentate pillar, monodentate pendant), creating a stable hierarchical structure.
• The framework exhibited ligand-to-metal charge transfer luminescence, selectively quenched by Rhodamine 6G (R6G).

Conclusions:

• A versatile strategy for stabilizing large aromatic linkers in metal phosphate frameworks was demonstrated.
• The developed material serves as a durable solid-state platform for luminescent molecular recognition and sensitive dye detection (limit of detection: 2.52 × 10^-6 M).
• Efficient donor-to-acceptor energy transfer confirmed as the sensing mechanism for R6G detection.