Liquid injection field desorption/ionization of reactive transition metal complexes

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Organometallic Chemistry

Background:

• Transition metal complexes are often sensitive to air and moisture, complicating their analysis.
• Characterizing reactive organometallic compounds requires specialized techniques to maintain sample integrity.

Purpose of the Study:

• To apply Liquid Injection Field Desorption/Ionization (LIFDI) mass spectrometry for the identification of reactive transition metal complexes.
• To demonstrate the utility of LIFDI for analyzing nickel and rhodium complexes in solution.

Main Methods:

• LIFDI mass spectrometry was employed using a double-focusing magnetic sector instrument.
• Reactive complexes were introduced as dilute solutions (approx. 0.2 mg/mL) in organic solvents (toluene, THF, acetonitrile) under inert conditions.
• A unique injection capillary delivered samples to the field desorption emitter within the ion source vacuum.

Main Results:

• Intense molecular ion peaks were observed for the target transition metal complexes.
• Analysis allowed for the identification of compounds by detecting molecular ions or neutral ligand loss.
• Byproducts of synthesis and decomposition were also detected, providing further insights.

Conclusions:

• LIFDI is a powerful technique for the direct analysis of air- and moisture-sensitive transition metal complexes.
• The method facilitates the characterization of reactive organometallic compounds by mass spectrometry.
• LIFDI offers a reliable approach for identifying target compounds and potential impurities in synthetic mixtures.