The absorption spectra of the three tautomeric forms of 2,5-dimercapto-1,3,4-thiadiazole have been determined by using the N- and S-methyl derivatives. In the ultraviolet region, a hypsochromic shift in absorption maxima is shown in the change from the dithionic to the thionic–thiolic and to the dithiolic forms. Strong bands in the infrared at 1508–1475 cm−1 and 1435–1415 cm−1 have been assigned to [Formula: see text]respectively.
通过使用N-和S-甲基衍生物,确定了2,5-二巯基-1,3,4-噻二唑三种互变异构体的吸收光谱。在紫外区域,当从二硫醇形式变为硫醇-硫醇形式,再变为二硫醇形式时,吸收峰出现了明显的红移。在红外区域1508-1475 cm-1和1435-1415 cm-1处的强吸收带分别被归属为[公式:见文本]。