Cold-spray ionization mass spectrometry: applications in structural coordination chemistry

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Biochemistry

Background:

• Electrospray ionization (ESI)-mass spectrometry (MS) is limited in characterizing labile supramolecules due to ion instability and thermal decomposition.
• Conventional MS techniques struggle with the precise analysis of non-covalent complexes and unstable organic species in solution.

Purpose of the Study:

• To introduce and demonstrate Cold-Spray Ionization (CSI) as a superior MS technique for labile species.
• To showcase the application of CSI-MS in analyzing complex biomolecular and organometallic structures.
• To present a novel metal-complex-based ionization probe for enhanced CSI-MS performance.

Main Methods:

• Utilizing a variant of ESI-MS operating at low temperatures (CSI).
• Employing metal-complex-based ionization probes with 2,6-bis(oxazolinyl) pyridine (pybox) ligands.
• Analyzing labile supramolecules, biomolecular complexes, organometallic compounds, and carbon clusters in solution.

Main Results:

• CSI-MS successfully detected labile non-covalent complexes, overcoming limitations of conventional MS.
• The novel pybox-ligand probes enabled detection of multiply charged ions from large, complex molecules, including biomolecules and fullerenes.
• Isotope-labeled probes clearly identified isotopic labeling shifts in biomolecules and carbon clusters.

Conclusions:

• CSI-MS is a powerful tool for characterizing unstable and complex supramolecular systems in solution.
• The developed ionization probes significantly enhance the capability of CSI-MS for analyzing diverse labile molecules.
• CSI-MS offers new avenues for investigating dynamic behavior and structural elucidation of challenging chemical and biological entities.