In:
The Journal of Chemical Physics, AIP Publishing, Vol. 158, No. 15 ( 2023-04-21)
Abstract:
The decarboxylation dynamics of the doubly deprotonated fluorescein dianion, Fl2−, are investigated by recording fragment action spectra for the anion, Fl−, and its decarboxylated analog, Fl–CO2−, using a new reflectron secondary mass spectrometer. The formation of the anion, Fl−, is directly investigated by photoelectron imaging. The Fl− and Fl–CO2− action spectra indicate that, for λ & lt; 400 nm, one-photon dissociative photodetachment, i.e., simultaneous decarboxylation and electron loss, competes with photodetachment, whereas for λ & gt; 400 nm, decarboxylation only proceeds following electron loss via a sequential two-photon process. The primary decarboxylation pathway is the ready loss of CO2 from the relatively short-lived intermediate excited state, Fl−[D1], which is formed by electron loss from the dianion via resonant tunneling through the repulsive Coloumb barrier associated with a high-lying excited dianion state, Fl2−[S2] .
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
2023
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
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