2 5 dimercapto 1 3 4 thiadiazole derivative July 8, 2019 16 32 64 128 2 5-dimercapto-1 3 4-thiadiazole 2 5-dimercapto-1 3 4-thiadiazole (dmtd) 2 5-dimercapto-1 3 4-thiadiazole solubility 2 5-dimercaptoterephthalic acid