Ã 2A1 → X̃ 2B1 emission spectrum of cis-1,2-difluoroethylene cation and the non-radiation decay of the Ã states of the haloethylene cations in the gaseous phase

doi:10.1016/0301-0104(79)80069-5

Chemical Physics

Volume 44, Issue 1, 15 November 1979, Pages 131-136

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Abstract

The results of the search for the Ã → X̃ radiative relaxation of haloethylene cations in the gaseous phase are reported. Only in the case of cis-1,2-difloroethylene cation was an emission spectrum detected. It is identified as the Ã ²A₁ → X̃ ²B ₁ band system on the basis of photoelectron spectroscopic measurements. An assignment of the emission bands yields the vibrational frequencies of four of the A₁ fundamentals (under C₂, symmetry) for the X̃ state and one for the Ã state. Well resolved Ne(I) photoelectron spectra of cis- and trans-1,2-difluoroethylene are presented, from which some vibrational frequencies for these cations in the X̃ and Ã states are also obtained. The lifetimes of cis-1,2-difluoroethylene cation in the lowest vibrational levels of the Ã ²A₁ state have been measured. The decay of this cation is unusual as these levels are depleted both by, radiative, and pathways leading to fragment ions (C₂HF⁺). The lack of detectable emissions with other fluoro-, chloro- and bromo-ethylene cations is discussed and the likely symmetries of the Ã states are proposed.

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Ã 2A1 → X̃ 2B1 emission spectrum of cis-1,2-difluoroethylene cation and the non-radiation decay of the Ã states of the haloethylene cations in the gaseous phase

Abstract

Intern. J. Mass Spectrom. Ion Phys.

Chem. Phys. Letters

Intern. J. Mass Spectrom. Ion Phys.

Chem. Phys.

Chem. Ber.

J. Electron Spectry.

Nouv. J. Chim.

Z. Naturforsch.

Ã ²A₁ → X̃ ²B₁ emission spectrum of cis-1,2-difluoroethylene cation and the non-radiation decay of the Ã states of the haloethylene cations in the gaseous phase