Studies in Fluorinated 1,3-Diketones and Related Compounds, Part VII : Mass Spectra of Some New Fluorinated Cu(II) 1,3-Diketonates

Department of Chemistry, University of Rajasthan, Jaipur-302 004

National Chemical Laboratory, Poona- 8

Manuscript received 14 October 1976, revised 20 January 1978, accepted 12 June 1978

The mass spectra of seven new fluorinated Cu(II) 1,3-diketonates of the general structure, L₂Cu (where L is a fluorinated 1, 3-diketone anion) have been recorded and discussed. These spectra show some preferential fragmentation pattern, (except compd. No. 7), the most strinking characteristic being the stepwise removal of alkyl/ perfluoroalkyl substituents. Substitution of alkyl group by perfluoroalkyl group in these chelates lead to more extensive fragmentation of the molecular ions. Migration of hydrogen atom has been observed in some of the fragments. The loss of ^.F, ^.CF₃ , ·C₂F₅ and ·CH₃ radicals has been observed from molecular ion, and may be interpreted as due to vinylic cleavage. A few doubly charged ions have also been observed. In all cases the base peak is due to ArCO⁺. A number of noteworthy metastable peaks due to transitions such as (L₂Cu-R)⁺→(L₂Cu-2R)⁺. and Ar-C\(\equiv\)O⁺→Ar⁺ are observed. All chelates exhibit a strong peak due to L⁺, the formation of which may be attributed to a valence change of bivalent to univalent state such as L₂Cu⁺.→L⁺ + LCu.