Adamantane-based Bidendate Metal Complexes in Crystalline and Solution State.

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Bidentate organic molecules featuring imidazole or benzimidazole groups serve as versatile building blocks.
• These molecules, linked by a rigid 1,3-diphenyladamantane spacer, are key to constructing supramolecular assemblies.
• Metal-coordination is a primary method for assembling these structures in the solid state.

Purpose of the Study:

• To investigate the self-assembly of supramolecular architectures using novel bidentate organic molecules.
• To explore the influence of ligand structure (imidazole vs. benzimidazole) on the resulting coordination polymers.
• To characterize the metal-ligand complexes formed and their supramolecular structures.

Main Methods:

• Single-crystal X-ray analysis to determine the solid-state structures of coordination complexes.
• Metal-coordination reactions using cobalt(II) or cadmium(II) ions with bidentate ligands.
• Cold-spray ionization mass spectrometry (CSI-MS) to analyze complexation ratios and detect coordination oligomers.

Main Results:

• Complexation of imidazole-bearing ligands with Co(II) or Cd(II) yielded doubly-interpenetrated 2D sheets.
• Complexation of benzimidazole-bearing ligands with Co(II) resulted in extended zigzag 1D chains.
• CSI-MS confirmed metal-ligand ratios (1:2 for imidazole, 1:1 for benzimidazole) consistent with X-ray analysis.
• Large molecular weight coordination oligomers were detected in coordination polymers via CSI-MS/MS.

Conclusions:

• Ligand design, specifically molecular shape and bulkiness, is critical for controlling the dimensionality of coordination polymers.
• The study demonstrates a method for creating diverse supramolecular architectures through tailored ligand synthesis and metal-coordination.
• Combined crystallographic and mass spectrometry techniques provide comprehensive characterization of coordination complexes and polymers.