A sulfur coordination polymer with wide bandgap semiconductivity formed from zinc(II) and 5-methylsulfanyl-1,3,4-thiadiazole-2-thione

The sulfur coordination polymer catena-poly[zinc(II)-μ2-bis[5-(methyl­sulfan­yl)-2-sulfanyl­idene-2,3-di­hydro-1,3,4-thia­diazol-3-ido-κ2N3:S]], [Zn(C3H3N2S3)2]n or [Zn2MTT4]n, constructed from Zn2+ ions and 5-methyl­sulfanyl-1,3,4-thia­diazole-2-thione (HMTT), was synthesized successfully and structurally char­acterized. [Zn2MTT4]n crystallizes in the tetra­gonal space group I\overline{4} (No. 82). Each MTT− ligand (systematic name: 5-methyl­sulfanyl-2-sulfanyl­idene-2,3-di­hydro-1,3,4-thia­diazol-3-ide) coordinates to two different ZnII ions, one via the thione group and the other via a ring N atom, with one ZnII atom being in a tetra­hedral ZnS4 and the other in a tetra­hedral ZnN4 coordination environment. These tetra­hedral ZnS4 and ZnN4 units are alternately linked by the organic ligands, forming a one-dimensional chain structure along the c axis. The one-dimensional chains are further linked via C—H⋯N and C—H⋯S hydrogen bonds to form a three-dimensional network adopting an ABAB-style arrangement that lies along both the a and b axes. The three-dimensional Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots confirm the major inter­actions as C—H⋯S hydrogen bonds with a total of 35.1%, while 7.4% are C—H⋯N hydrogen-bond inter­actions. [Zn2MTT4]n possesses high thermal and chemical stability and a linear temperature dependence of the bandgap from room temperature to 270 °C. Further investigation revealed that the bandgap changes sharply in ammonia, but only fluctuates slightly in other solvents, indicating its promising application as a selective sensor.