Li X, Sawada K, Shioji H. Determination and gas-phase stability evaluation of metal complexes by nanoelectrospray ionization and collision-induced dissociation tandem mass spectrometry.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023;
37:e9649. [PMID:
37953546 DOI:
10.1002/rcm.9649]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 11/14/2023]
Abstract
RATIONALE
The structures of metal complexes determine their stable functioning in product performance. Electrospray ionization mass spectrometry (ESI-MS) is used in studying metal complexes despite exhibiting limitations in analyzing labile complexes. Therefore, identifying a method for detecting unstable complexes and evaluating their stabilities is necessary, providing a theoretical basis for material selection and performance evaluation.
METHODS
The standard complexes Zn(BTZ)2 , Fe(acac)3 , and Sn(Oct)2 were analyzed using nanoESI quadrupole orbitrap MS (nanoESI-MS) and compared with ESI-MS for two temperature modes. The three complexes and alkylamine-Ag+ complexes were analyzed using nanoESI and collision-induced dissociation MS/MS (CID-MS/MS). Breakdown plots of the survival yield against collision energies expressed in terms of the center-of-mass were constructed according to the obtained product ion spectra. Quantum chemical calculations based on density functional theory were performed to calculate the binding energies between the alkylamines and Ag+ .
RESULTS
The three standard complexes were detected in the native structures using nanoESI-MS, confirming the advantage of nanoESI over ESI for detecting unstable complexes. The gas-phase stabilities of the amine-Ag+ complexes, estimated using the breakdown plots constructed by plotting the data obtained via nanoESI and CID-MS/MS, were consistent with the established theories, previous studies, and binding energies calculated using computational methods.
CONCLUSIONS
NanoESI-MS is suitable for detecting labile complexes and enables the structural analyses of unknown complex additives. A novel approach based on nanoESI and CID-MS/MS was developed to determine the gas-phase stabilities of complexes, enabling their quantification and comparison and providing a technical basis for product improvement, which is essential in developing industrial materials.
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