Evaluation of the reduction of imidazophenazine dye derivatives under fast‐atom‐bombardment mass‐spectrometric conditions

Abstract

Satellite [M + 2](+*) and [M + 3](+) peaks accompanying the common peak of the protonated molecule [M + H](+) that are known to indicate the occurrence of a reduction process were observed in the fast atom bombardment (FAB) mass spectra of imidazophenazine dye derivatives in glycerol matrix. The distribution of the abundances in the [M + nH](+) peak group varied noticeably for different derivatives. This indicated different levels of the reduction depending on the different structure variations of the studied molecules. In the search for correlations between the mass spectral pattern and the structural features of the dyes, ab initio HF/6-31++G** quantum chemical calculations were performed. They revealed that the abundances of the [M + 2](+*) and [M + 3](+) ions show growth proportional to the decrease of the energy of the lowest unoccupied molecular orbital, i.e. proportional to the increase of the electron affinity of the dye molecule. A method for rapid screening of reductive properties of sets of dye derivatives on the basis of the FAB mass spectral data is discussed.

Sensitivity of redox reactions of dyes to variations of conditions created in mass spectrometric experiments

“…The aim of the present work was to probe the effect of variation of mass spectrometric experimental conditions, in particular the balance of protons and electrons, on the extent of reduction reactions on the example of a set of imidazophenazine dye derivatives (Scheme ). It was revealed in our previous work15 that differences in the electronic structure of the imidazophenazine derivatives, caused by variation of substituents in the imidazole ring, correlated with the extent of reduction observed under FAB conditions. These dyes similar in structure but distinct in electron affinity and ionization energy are suitable as test compounds sensitive to variations of environmental parameters significant for redox processes.…”

“…It is known that reduction reactions of organic compounds can proceed under secondary ion mass spectrometry (SIMS), fast atom bombardment (FAB), laser desorption/ionization (LDI), matrix‐assisted laser desorption/ionization (MALDI), desorption/ionization on porous silicon (DIOS) conditions 2–15. A brief overview of the relevant current literature can be found in recent papers on reduction of dyes 14, 15. One of the reduction scenarios consists of simultaneous or concomitant attachment of an electron and a proton (comprising a hydrogen atom as a whole) to an analyte molecule (M).…”

Reaction mechanisms of methylene-blue degradation in three-dimensionally integrated micro-solution plasma

“…n = 3 or higher is possible when the analyte is MB. 31,32) Thus, we focused on one or two species with similar time evolution characteristics. single exponential function with a time constant of τ = 0.095 min.…”

Redox interactions of methylene blue with cysteine amino acid as a possible mechanizm of biological action of the dye

“…На уровне малых молекул активно разрабатывались масс-спектрометрические подходы к изучению окислительновосстановительных свойств редокс-активных веществ [52][53][54], в частности редоксактивных красителей [55,56] и метиленовoго синего в их числе [57,58]. При использовании методов вторично-ионной масс-спектрометрии (ВИМС), бомбардировки быстрыми атомами (ББА), матрично-активированной лазерной десорбции/ионизации (МАЛДИ) нами установлены особенности редокс-превращений метиленового синего в зависимости от метода воздействия и окружающей среды [59][60][61][62][63][64][65].…”