Архивы рубрики ‘Chemistry and Applications of Leuco Dyes’


It is remarkable that more than a century after the discovery of tetrazoliums, they continue to have wide applications. In particular, the reductive ring opening reaction leading to formazans continues to receive a lot of attention. In 1993, there were 316 citations to tetrazolium salts in Chemical Abstracts, 23 of which were to their reduction. […]


The combination of a positive charge and reducibility of tetrazolium salts finds use as anticorrosion agents for metals.634,635 The y are compo­nents of an oxidant/etchant bath composition for silicon dioxide corrosion — resistant surfaces.636 They are also used as antistatic agents in polyamide yarns.637,638 Tetrazolium salts have found use as phase transfer catalysts in the […]

Nonsilver Photography

For convenience, the applications of tetrazolium salts to nonsilver photography will be divided into two sections: photochemical systems and photoconductive systems. Photochemical systems are similar to the silver halide-based systems in that light causes a stoichiometric chemical change (a latent image) which can be amplified (developed) to an image either by heat or by activation […]

Silver Halide Photography

Various aspects of silver halide photographic theory and practice are discussed in many textbooks notably the Mees and James series.579 Al­though a three-color system can be designed based on three tetrazolium salts that would lead to yellow, magenta, and cyan formazan dyes, there is only one reference to such a system, involving the use of […]


Wilkinson’s treatise on applications of coordination compounds in­cludes a chapter that describes the use of formazan/tetrazolium systems in both conventional silver halide and nonsilver photographic applica­tions.5 78

Nonclinical Uses

Tetrazolium salts have found use in a number of industries both in the detection of bacterial contamination and in process analysis. They are used in meat,551 fisheries,552 mi1k,553,557,558 tanneries,554 and the canning indus — tries.555,556 Tetrazolium reduction is used to monitor a number of processes in agriculture such as the viability of seed, pollen, yeast, […]

Clinical Uses

Levels of a number of metabolites as well as a number of enzymes in body fluids are indicative of disease conditions. Many of the enzymatic reactions mentioned above have been used in solution clinical assays as well as in test strips.446,497-508’512-515 Assays for hydrogen peroxide and the enzyme peroxidase using NADH and a tetrazolium salt […]


The biological applications of tetrazolium salts are the subject of a textbook.96 Kuhn and Jerchel74 were the first to recognize the utility of tetrazolium salts as indicators in redox enzyme activity, particularly those of the various dehydrogenases. It has been recognized449 that this particular utility of tetrazolium salts is related to the proximity of their […]

The Determination of Metal Ions

The ability of metal ions to form complexes with formazans is utilized to determine these ions either directly (for low valent reducing ions) or indirectly in the presence of a reducing agent. Among others, molybdenum(VI) and vanadium(V) have been determined using this method.442,443 Indirect methods have been reported for the analyses of substances that do […]


Most analytical uses of tetrazolium salts utilize their reducibility. The ability of the resulting formazan to coordinate to metal ions, causing a characteristic shift in the spectrum, is often utilized to determine the metal ions or to enhance the sensitivity of the detection. Determination of Reducing Substances A number of reducing agents have been […]