Introducing Seven Transition Metal Ions into Terpyridine-Based Supramolecules: Self-Assembly and Dynamic Ligand...

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• 2,2′:6′,2″-terpyridine (tpy) is crucial for constructing supramolecular architectures via ⟨tpy-M-tpy⟩ connectivity.
• Previous self-assembly of large discrete structures was limited to Cd(II), Zn(II), and Fe(II) ions.

Purpose of the Study:

• To broaden the scope of metal ions used in tpy-based supramolecular self-assembly.
• To synthesize novel supramolecular fractals using a diverse range of transition metals.
• To investigate the gas-phase stability and solution-phase ligand exchange kinetics of these new structures.

Main Methods:

• Coordination-driven self-assembly using seven divalent transition metal ions (Mn, Fe, Co, Ni, Cu, Zn, Cd).
• Mass spectrometry for analyzing structural stability in the gas phase.
• Kinetic studies to determine ligand exchange rates in solution.

Main Results:

• Successfully assembled supramolecular fractals with seven different divalent metal ions.
• Reported for the first time the formation of large, discrete structures with ⟨tpy-M-tpy⟩ connectivity using Mn(II), Co(II), Ni(II), and Cu(II).
• Established the relative order of gas-phase structural stability and revealed metal-dependent coordination inertness in solution.

Conclusions:

• The study significantly expands the metal ion repertoire for tpy-based supramolecular assembly.
• Provides fundamental insights into the stability and reactivity of these novel supramolecular systems.
• Offers guidance for future research in tpy-based supramolecular chemistry, including self-assembly, characterization, and applications.