Non-interpenetrated square-grid coordination polymers synthesized using an extremely long N,N'-type ligand

Area of Science:

• Coordination Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Development of novel ligands is crucial for designing advanced coordination polymers.
• Understanding structure-property relationships in metal-organic frameworks is an active research area.

Purpose of the Study:

• To synthesize and characterize new non-interpenetrated square-grid coordination polymers.
• To investigate the structural diversity and interconversion of cadmium-based frameworks.
• To explore the role of the ligand (L) in dictating framework topology and properties.

Main Methods:

• Solvothermal synthesis of four coordination polymers: [Mn(L)2(NO3)2]infinity (1), [[Cd(L)2(NO3)2].solvate]infinity (2), [Cd(L)2(NO3)2]infinity (3), and [[Zn(L)2](BF4)2.(C6H6)2.564.(DMF)1.576.(MeOH, H2O)3.454]infinity (4).
• Utilized a new, extremely long N,N'-type ligand: 2,5-bis(4'-(imidazol-1-yl)benzyl)-3,4-diaza-2,4-hexadiene (L).
• Single-crystal X-ray diffraction for structural determination and analysis of framework interconversion.

Main Results:

• Successfully synthesized four new square-grid coordination polymers incorporating Mn, Cd, and Zn metal centers.
• Two distinct cadmium coordination polymers, [Cd(L)2(NO3)2]infinity, were obtained, differing in ligand arrangement.
• A channel-containing cadmium structure converts to a more condensed, stable form upon guest molecule removal.

Conclusions:

• The new ligand (L) is effective in constructing diverse non-interpenetrated coordination polymer architectures.
• Solvent choice influences the formation of different topological forms of cadmium-based frameworks.
• The observed structural transformation highlights the dynamic nature of coordination polymers and guest-host interactions.