In Situ Metal-Assisted Ligand Modification Induces Mn₄ Cluster-to-Cluster Transformation: A Crystallography, Mass...

Area of Science:

• Coordination Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• The dehydration of (S,S)-1,2-bis(1H-benzo[d]imidazol-2-yl)ethane-1,2-diol (H4L) is a key transformation.
• Understanding metal-assisted reactions under solvothermal conditions is crucial for materials synthesis.

Purpose of the Study:

• To investigate the metal-assisted dehydration of H4L under solvothermal conditions.
• To elucidate the mechanism of coordination cluster formation and transformation.
• To characterize the resulting manganese complexes and their structural evolution.

Main Methods:

• Solvothermal synthesis using H2O/CH3OH.
• Single-crystal X-ray diffraction (XRD) for structural determination.
• Electrospray Ionization Mass Spectrometry (ESI-MS) for solution and solid-state analysis.

Main Results:

• Formation of two manganese coordination clusters: [Mn4(H3L)4Cl2]Cl2·5H2O·5CH3OH (Mn4L4) and [Mn4(H2L')6(μ3-OH)]Cl·4CH3OH·H2O (Mn4L'6).
• Proposed mechanism involving stepwise assembly, disassembly, ligand modification, and reassembly.
• Identification of intermediate clusters [Mn4LxL'6-x] (x=5, 4, 3, 2, 1).

Conclusions:

• The study reveals a complex transformation pathway between coordination clusters.
• Multiple phase transformations are possible, even if not observed in the crystalline state.
• Provides a deeper understanding of "black-box" reactions involving coordination clusters.