Chromogenic Detection of Mimic Organophosphorus Nerve Agent DCP Mediated by Novel Rhodium(II) Paddlewheel Complexes

Author

Eric D. Fussell, University of Tennessee, KnoxvilleFollow

Date of Award

12-2023

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Chemistry

Major Professor

Ampofo Darko

Committee Members

Michael Best, Andrew Steen, David Jenkins

Abstract

Chemical warfare agents (CWA) are amongst mankind’s most devastating inventions. Organophosphorus nerve agents (OPNA) are a particularly potent class of these compounds in part due to relatively low LD₅₀s, quick times of death, and their persistence in the environment. Though OPNAs originated in the 1930’s, derivatives are still used by terrorist organizations around the world as a method of mass murder. One of the many examples of these agents being used to annihilate human lives was the 2013 attack where one of these OPNAs was used to kill almost 1500 civilians with a single strike in Syria. Tragedies such as this necessitate timely and specific detection of the OPNAs for both civilian emergency response and military use.

A detector motif has been developed to fill this need. Instrument based detectors are unnecessarily heavy and expensive, so this method instead uses a chromogenic Rh(II) paddlewheel complex (Rh(II)) as the detector. It operates on the principle that the observed color of the Rh(II) is dependent on which moiety is bound to its axial sites. Using a Lewis base (LB) to degrade the OPNA produces class specific degradation products, which produce OPNA family dependent chromogenic responses.

In this dissertation two main types of Rh(II)-LB compounds were synthesized: axially tethered and untethered Lewis bases. Each was tested against the G-series simulant diethyl chlorophosphate (DCP). Both classes of Rh(II) were effective for detecting DCP, with the untethered complexes having a lower limit of detection. Ultimately both types of Rh(II) top performing compounds were able to selectively without false positives from commonly encountered interferents.

These detectors have the potential to revolutionize OPNA detection by providing a robust, selective and rapid sensing solution that could detect all families of OPNAs, including the latest and most deadly, Novichok agents.

Recommended Citation

Fussell, Eric D., "Chromogenic Detection of Mimic Organophosphorus Nerve Agent DCP Mediated by Novel Rhodium(II) Paddlewheel Complexes. " PhD diss., University of Tennessee, 2023.
https://trace.tennessee.edu/utk_graddiss/9020