Cationic magnesium hydride [MgH]⁺ stabilized by an NNNN-type macrocycle

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Main Group Chemistry

Background:

• Magnesium hydride complexes are important in catalysis and synthesis.
• Macrocyclic ligands offer unique coordination environments for metal centers.
• Understanding the reactivity of magnesium hydride cations is crucial for developing new synthetic methodologies.

Purpose of the Study:

• To synthesize and characterize a magnesium hydride cation supported by a macrocyclic ligand.
• To investigate the reactivity of this novel magnesium hydride cation with unsaturated substrates.

Main Methods:

• Synthesis of the magnesium hydride cation [(L)MgH]+ via partial protonolysis of a mixed amide hydride precursor.
• Characterization of the product using spectroscopic techniques.
• Reaction studies with unsaturated substrates, including pyridine.

Main Results:

• Successful preparation of the magnesium hydride cation [(L)MgH]+, where L = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane (Me4TACD).
• Demonstration of the cation's reactivity towards unsaturated substrates.
• Observation of reactions with pyridine, indicating its potential as a synthetic reagent.

Conclusions:

• The macrocyclic ligand Me4TACD effectively stabilizes the magnesium hydride cation.
• The [(L)MgH]+ complex exhibits versatile reactivity with unsaturated organic molecules.
• This work expands the known chemistry of magnesium hydride cations and their applications.