Formation and Fragmentation Chemistry of Tripositive Ln(TMGA) 3 3+ Complexes in the Gas Phase

• Published in: Journal of the American Society for Mass Spectrometry 2017-08, Vol.28 (8), p.1696-1701
• Main Authors: Chen, Xiuting, Li, Qingnuan, Gong, Yu
• Format: Article
• Language: English
• Subjects: Fragmentation; Ionization; Ions; Mass spectrometry; Reduction
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1007/s13361-017-1681-4

Electrospray ionization (ESI) of LnCl (Ln = La-Lu except Pm) and TMGA (tetramethyl glutaramide) mixtures resulted in the formation of gas-phase Ln(TMGA) complexes, where tripositive lanthanide cation was coordinated by three neutral TMGA ligands. Collision induced dissociation (CID) was employed to investigate the fragmentation chemistry of these tripositive complexes. Ln(TMGA) (TMGA- 45) resulting from C -N bond cleavage of TMGA and hydrogen transfer is the major CID product for all Ln(TMGA) except Eu(TMGA) which predominantly forms divalent Eu (TMGA) complex via loss of TMGA . Analogous Yb (TMGA) and Sm (TMGA) complexes arising from charge reduction were also observed, in competition with the formation of charge conserving Yb (TMGA)(TMGA-H) and Sm (TMGA)(TMGA-H) products. The yield of these charge reducing products follows their reduction potentials in condensed phase. In addition to Ln(TMGA) , tripositive ions such as Ln(TMGA) and Ln(TMGA) were experimentally identified as well. While the former was observed along with Ln(TMGA) during ESI, the latter was observed upon CID of Ln(TMGA) , suggesting two TMGA molecules can stabilize Ln in the gas phase. Graphical Abstract ᅟ.