Multinuclear luminescent Schiff-base Zn-Nd sandwich complexes.

Area of Science:

• Coordination Chemistry
• Materials Science
• Photophysics

Background:

• Schiff-base ligands are versatile building blocks for constructing complex metal architectures.
• Tuning the metal-to-ligand ratio and counterions allows for control over the stoichiometry and structure of coordination complexes.
• Lanthanide complexes are known for their unique luminescent properties, particularly in the near-infrared region.

Purpose of the Study:

• To synthesize and characterize novel multinuclear 3d-4f metal complexes using a Schiff-base ligand.
• To investigate the influence of metal ratios and counterions on the resulting complex structures.
• To explore the photophysical properties, specifically near-infrared luminescence, of these synthesized complexes.

Main Methods:

• Synthesis of multinuclear complexes employing bis(3-methoxysalicylidene)ethylene-1,2-phenylenediamine (H(2)L) ligand.
• Stoichiometric control using varying Zinc (Zn) to Neodymium (Nd) ratios.
• Structural characterization of trinuclear, tetranuclear, and dinuclear complexes using X-ray crystallography and elemental analysis.
• Spectroscopic investigation to determine near-infrared (NIR) luminescence properties.

Main Results:

• Formation of multinuclear 3d-4f complexes with sandwich-like molecular structures.
• Isolation and characterization of trinuclear ([Nd(ZnL)2(NO3)2(H2O)2].NO3.EtOH.H2O and [Nd(ZnL)2Cl2(H2O)3].Cl.2MeOH.5H2O), tetranuclear ([Nd2(ZnL)2Cl6(MeOH)2].MeOH), and dinuclear ([NdZnL(NO3)3MeCN].MeCN) complexes.
• Observation of near-infrared (NIR) lanthanide luminescence in the synthesized complexes.

Conclusions:

• The Schiff-base ligand H(2)L effectively forms diverse multinuclear 3d-4f complexes.
• Stoichiometry and counterions play a crucial role in dictating the final molecular architecture.
• The synthesized complexes exhibit promising NIR luminescence, suggesting potential applications in optical materials and sensing.