Structure and powder diffraction pattern of 2,4,6-Trimercapto-s-triazine, trisodium salt (Na 3 S 3 C 3 N 3 ·9H 2 O)

2,4,6-Trimercapto-s-triazine, trisodium salt (ideally, Na 3 S 3 C 3 N 3 ·9H 2 O), also known as TMT-55, is a white powder that is used to precipitate heavy metals from contaminated waters. Chemical analyses confirmed the nominal composition. TMT-55 crystals are uniaxial negative with indices of refraction (25 °C) of n ε =1.520 and n ω =1.675. The structure was determined by single-crystal methods at 25 and −110 °C. A powder pattern was determined and compared to a simulated pattern based on the 25 °C structure data. Crystal data at 25 °C are: R 3; Z =6; a =17.600(1) Å and c =9.720(2) Å; V =2607.5(5) Å 3 ; D x =1.55 g/cm 3 .