The crystal structures of three 3-methyl-1H-1,2,4-triazole-5-thio­nes, including a second polymorph of 4-[(E)-(5-bromo-2-hy­droxy­benzyl­idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione and a redetermination of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione

摘要: The structures of three 3-methyl-1H-1,2,4-triazole-5-thione derivatives are reported. structure 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C3H6N4S, (I), has been redetermined with an improved model for the H atoms: non-H atoms (I) all lie on mirror planes in space group Pbcm, and methyl disordered over two sets reflection-related atomic sites having occupancy 0.5: independent N—H⋯S hydrogen bonds link mol­ecules compound into complex sheets. 4-[(E)-(3,4-di­meth­oxy­benzyl­idene)amino]-3-methyl-1H-1,2,4-tri­azol-5(4H)-thione, C12H14N4O2S, (II), despite lying general positions close to planar, a dihedral angle between rings 6.31 (10)°: (II) linked by three-centre N—H⋯(O)2 bond C(10)C(11)[R12(5)] chain rings. A second polymorph 4-[(E)-(5-bromo-2-hy­droxy-5-bromo­benzyl­idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C10H9BrN4OS, (III), identified; nearly co-planar 1.9 (4)°. There is intra­molecular O—H⋯N bonds, forming centrosymmetric R22(8) dimers. Comparisons made some related structures.