Coordination of Triply Charged Lanthanum in the Gas Phase: Theory and Experiment

✍ Scribed by Tujin Shi; Alan C. Hopkinson; K. W. Michael Siu

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 739 KB
• Volume: 13
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200601074

✦ Synopsis

Abstract

Ion–molecule reactions between complexes [La(CH~3~CN)~n~]^3+^ (n=6–9) or [La(NC(CH~2~)~4~CN)~n~]^3+^ (n=3–4) and water were studied at low collision energies in the second quadrupole of a tandem mass spectrometer. The products [La(CH~3~CN)~p~(H~2~O)~8−p~]^3+^ (p=6–8) and [La(NC(CH~2~)~4~CN)~q~(H~2~O)~8−2__q__~]^3+^ (q=3–4) had the highest relative abundances. This strongly suggests that the preferred coordination number of La^3+^ is eight. Similarly, the coordination number of Ca^2+^ was re‐examined both experimentally and theoretically, and was found to be six, in good agreement with previous observations. Density functional calculations provide strong evidence that the primary solvation shell of [La(L)~n~]^3+^ consists of eight ligands; additional ligands reside in a second solvation shell and are hydrogen bonded to one or two water molecules in the first shell.