Two New Coordination Polymers: Crystal Structures and Fluorescence Properties

Area of Science:

• Coordination Chemistry
• Materials Science
• Luminescence

Background:

• Metal-organic frameworks (MOFs) and Schiff base complexes are crucial in materials science due to their tunable structures and properties.
• Investigating novel complexes with transition metals and rare-earth elements can lead to new functional materials.
• Luminescent materials are essential for applications in sensing, lighting, and imaging.

Purpose of the Study:

• To synthesize and characterize new Ni(II) metal-organic frameworks and a rare-earth dinuclear Schiff base complex.
• To investigate the structural and luminescent properties of the synthesized compounds.
• To explore the potential of these complexes as fluorescent materials.

Main Methods:

• Solvothermal synthesis of metal complexes.
• Characterization using single-crystal X-ray diffraction, elemental analysis, FT-IR, powder X-ray diffraction, and thermogravimetric analysis.
• Fluorescence performance testing.

Main Results:

• Two novel complexes, [Ni2(HL)2(H2O)4]·3H2O (1) and [La2(dbm)4L·CH3OH] (2), were successfully synthesized.
• Complex 1 forms a rigid 3D framework, exhibiting a 13.7-fold fluorescence enhancement with deep blue emission.
• Complex 2 forms discrete zero-dimensional molecules with light blue fluorescence.

Conclusions:

• The synthesized Ni(II) MOF and La(III) Schiff base complex display distinct structural architectures and luminescence behaviors.
• The rigid framework and hydrogen bonding in complex 1 contribute to its significant fluorescence enhancement.
• These findings highlight the potential of the synthesized complexes as novel fluorescent materials.