Nonlinear optically active polymeric coordination networks based on metal m-pyridylphosphonates

Area of Science:

• Materials Science
• Inorganic Chemistry
• Crystallography

Background:

• Polymeric coordination networks offer tunable properties for advanced applications.
• Pyridylphosphonate ligands are versatile building blocks for constructing complex frameworks.
• Nonlinear optical (NLO) materials are crucial for photonics and optoelectronics.

Purpose of the Study:

• Synthesize and characterize novel polymeric coordination networks.
• Investigate the structural diversity and properties of these materials.
• Evaluate the nonlinear optical properties of the synthesized compounds.

Main Methods:

• Hydro(solvo)thermal synthesis of metal-organic frameworks.
• Single-crystal X-ray crystallography for structural determination.
• Powder second harmonic generation (SHG) measurements.

Main Results:

• Successfully synthesized four compounds: [M(2)(L-Et)(4)(mu-H(2)O)] (M = Mn, Co, Ni) and [Cd(L-H)(2)].
• Compounds 1-3 are isostructural with a 3D framework in a noncentrosymmetric space group (Fdd2).
• Compound 4 exhibits a centrosymmetric 3D network structure.
• Compounds 1-3 display significant powder second harmonic generation signals, exceeding that of potassium dihydrogen phosphate.

Conclusions:

• The study demonstrates the successful synthesis of pyridylphosphonate-based coordination networks with diverse structures.
• The noncentrosymmetric nature of compounds 1-3 correlates with their observed second harmonic generation properties.
• These findings highlight the potential of these materials for nonlinear optical applications.