Important of Azoles

Azoles are one of a cyclic derivatives of chemical heterocyclic chemical and organic compounds including g a five member di unsaturated ring structure composed of bi nitrogen atoms at position (3 and 4) and one sulfur atom at position (1). Most of prepared work on the four thiadiazoles has been on the 1, 3, 4-thiadiazoles. Physical, theoretical, and spectroscopic properties have been reviewed .

Zahradnik and Koutecky (6) made a series of studies and found that the calculated bond orders show a larger π-electron delocalization in the 1,2,5 than in the 1,3,4 isomer, in agreement with the results of Bak.The formal double bonds have a lower bond order in the 1,2,5 than in the 1,3,4-isomer, whereas the reverse is true for the formal single bonds.

Fig.(3) The four tautomeric forms of 2-amino-5-mercapto -1,3,4-thiadiazole
In the literature, amino-mercapto-1,3,4-thiadiazole, is described under different chemical names because of the differences in chemical terminology.However, in order to obtain a fuller understanding of the literature, the various terms are listed below.
AMT is a white-yellowish powdered crystalline solid, with a molecular weight of 133.19g/mol, melt at 227Cº.

4.Thiadiazoles uses
Among azoles, thiadiazole and its derivatives continue to draw the attention of synthetic organic chemists due to large group of compounds possessing a wide spectrum of uses.
In the field of archaeological conservation, amino-mercapto-1,3,4-thiadiazole is the most widely used corrosion inhibitor in the treatment of bronze artifacts (38) .