ISSN:
0951-4198
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
Crystalline Ce(C5H7O2)4 has been synthesized directly from the reaction of hydrated cerium(IV) oxide with acetylacetone, (C5H8O2), and its electron-ionization (EI) mass spectrom is reported. The compound exists as a monomer (mass 536) in the gaseous state. The mass spectrum, like those of M(C5H7O2)4 (M = Zr or Th) and CeL4 (L = fluorinated β-diketonate), shows the dominant ion signal to be due to the [Ce(C5H7O2)3]+ ion that arises from the loss of one C5H7O2 from the molecular ion. An internal electron-transfer affords [Ce(C5H7O2)3]+·. Fragmentation of [Ce(C5H7O2)3]+· to [Ce(C5H7O2)2]+ is similar to that observed for the tris-chelates of trivalent transition metals and La(C5H7O2)3. The ion [Ce(C5H7O2)2]+ ultimately breaks down to [CeO]+ through the sequential loss of three even-electron neutral species, CH3COCHCCH2, H2O and CH3COCHCCH2 without invoking any further reduction of the Ce centre. Mechanisms are given for the loss of the three even-electron species from the bis(acetylacetonato)cerium(III) ion fragment. Theoretical simulations of patterns of the fragment ions [Ce(C5H7O2)3]+·, [Ce(C5H7O2)2]+·, and [Ce(C5H7O2)OH]+ have been made and compared with those of the corresponding experimental results in support of the suggested mode of fragmentation.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/rcm.1290030911
