Correlation Engine 2.0
Clear Search sequence regions

Sizes of these terms reflect their relevance to your search.

2',7'-Dichloro- and 2',7'-difluorofluoresceins are superior alternatives to underivatized fluorescein. Although several studies characterizing their condensed-phase photophysical properties have been reported, little is known about their intrinsic characteristics. Here, the gas-phase properties of three charge states of each fluorescein are characterized using a quadrupole ion trap mass spectrometer which has been modified for spectroscopy. Electronic action spectra, constructed by monitoring the extent of photodissociation as a function of excitation wavelength, indicate that the gaseous dianions and cations resemble their solution-phase counterparts. In contrast, a large shift in the electronic action spectra of the monoanions indicates the presence of a different tautomer in the gas phase than that present in solution. The gaseous monoanion is deprotonated on the xanthene ring, rather than being deprotonated on the pendant group as found in soluion. The dianions and cations do not emit detectable fluorescence in the gas phase. In contrast, the monoanions do fluoresce, but the emission intensity is low and the spectra are broad. This work illustrates the effect of halogenation on the intrinsic properties of the dyes and provides useful fundamental understanding that promises to aid the development more robust fluorescent dyes.


Huihui Yao, Rebecca A Jockusch. Fluorescence and electronic action spectroscopy of mass-selected gas-phase fluorescein, 2',7'-dichlorofluorescein, and 2',7'-difluorofluorescein ions. The journal of physical chemistry. A. 2013 Feb 14;117(6):1351-9

Expand section icon Mesh Tags

Expand section icon Substances

PMID: 23323837

View Full Text