Chemical and photophysical studies on the interaction of reactive oxygen species with carbonylated diazo derivatives: Their chromogenic, fluorescent detection and mechanistic investigation

Abstract

Reactive oxygen species (ROS) like H2O2 and singlet oxygen (1O2) have an important role in living systems. A particular concentration of H2O2 is very necessary to regulate the physiological activities of cells. Both lower concentrations as well accumulation of H2O2 trigger varieties of diseases. Likewise, excessive 1O2 causes many dysfunctions and leads to many kinds of diseases. So, it is necessary to know the accurate concentration of H2O2 and 1O2 in a different system for safety. Here, we present a chemodosimeter approach to investigate the interactions of H2O2 and 1O2 by the use of diazo compounds through spectroscopy and investigate the reaction mechanism. Dakin and oxidative addition reactions were used respectively where probes showed a good color change and significant changes in absorbance and emission bands. Difluoride substituted diazo compound appeared to show a better limit of detection (4.75 μM at pH = 7.4) for H2O2, and the nitro derivative is found good for 1O2 (36 μM at pH = 9). For the validity of the result, we also carried out DFT quantum chemical studies. Raman and IR spectroscopy were used to investigate the reaction mechanism. Finally, we isolated the final products and characterized which interestingly showed an unusual de-nitration reaction during interactions of the probe with the H2O2 solution and an interesting blue-colored para-quinone derivative of the compound was also isolated.