Utilizing Experiment and Theory to Evaluate Rhodamine B ethylenediamine as a Fluorescent Sensor for G-type Nerve Agents

J Fluoresc. 2022 May;32(3):961-967. doi: 10.1007/s10895-022-02904-7. Epub 2022 Feb 26.

Abstract

Nerve gas mimic binding with Rhodamine B ethylenediamine (1) was studied in organic media. Binding of the nerve gas mimic, diethyl chlorophosphate (DCP), with the probe generated a non-fluorescent intermediate and a fluorescent product. Fluorescent and non-fluorescent products generated were identified using mass spectrometry and X-ray crystallography. Time-dependent density functional theory calculations were also used to investigate the electronic structure of the fluorescent probe in the ground and lowest lying π → π* singlet excited state. Though good agreement between theory and experiment can be obtained for the intense peak in the experimental spectrum using non-hybrid functionals, care must be taken when modelling these complexes due to the appearance of an n → π* transition that is too low in energy and appears to fall in the shoulders of the π → π* transitions.

Keywords: Computational; Fluorescence; Nerve Agents; Rhodamine; Sensor.

MeSH terms

  • Ethylenediamines
  • Fluorescent Dyes / chemistry
  • Nerve Agents* / chemistry
  • Rhodamines / chemistry

Substances

  • Ethylenediamines
  • Fluorescent Dyes
  • Nerve Agents
  • Rhodamines
  • rhodamine B