Česká společnost pro hmotnostní spektrometrii

(5. konference České společnosti pro hmotnostní spektrometrii - WeO-002)
Infrared and visible photodissociation spectra of rhodamine ions at 3 K in the gas phase

Juraj Jašík ¹, Rafael Navrátil ¹, Ivan Němec ², Jana Roithová ^1 *

1. Department of Organic Chemistry, Charles University in Prague
2. Department of Inorganic Chemistry, Charles University in Prague

Abstrakt

Rhodamines are class of compounds known for their interesting photophysical properties, e.g. high quantum yields and both excitation and emission in the visible area of the spectrum. Therefore they are widely used as dyes, gain mediums in dye lasers and fluorescent labels in various physical, chemical and biological applications [1].

In this work the first helium-tagging photodissociation spectra in the visible range (He@VisPD) using our special home-built instrument ISORI (Ion Spectroscopy of Reactive Intermediates) will be presented and demonstrated for the selected Rhodamine dyes (Rhodamine 123, Rhodamine 110 and Rhodamine 110’s silver salt) [2]. The ISORI instrument allows us to measure visible and infrared spectra of mass-selected ions in the gas phase at temperatures reaching 3 K [3]. At these conditions, helium–tagged ions are in their ground vibrational state. Upon single-photon absorption, Rhodamine He@VisPD spectra feature the Franck–Condon envelopes with strong 0–0 transition. Experimental vibrationally-resolved spectra agree very well with the theoretical predictions for the excitation from the ground singlet state S0 to the first singlet excited state S1. Nice agreement between the theoretical simulation of the Franck–Condon envelopes with the measured He@VisPD spectra implies a negligible effect of the helium atom on the structure of Rhodamine ions, and therefore on the spectra.

In addition, the helium-tagging infrared photodissociation (IRPD) of Rhodamine ions will also be presented and compared to the classical solid-state infrared spectra. Both the IRPD spectra from the gas-phase and the solid-state IR spectra are accompanied by theoretical predictions using DFT calculations.

* Korespondující autor: jana.roithova@natur.cuni.cz

Literatura

1. Sabnis R.W.: Handbook of Fluorescent Dyes and Probes. John Wiley & Sons, Hoboken, New Jersey (2015).
2. Jasik J. et. al.: J. Phys. Chem. A 119, 12648-12655 (2015).
3. Jasik J. et al.: Int. J. Mass Spectrom. 354-355, 204-210 (2013).

Poděkování:

The authors gratefully acknowledge financial support from the European Research Council (StG ISORI, No. 258299).