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‐polyzinc(II)‐μ₂‐bis5‐(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 (No. 82). Each MTT^? ligand (systematic name: 5‐methylsulfanyl‐2‐sulfanylidene‐2,3‐dihydro‐1,3,4‐thiadiazol‐3‐ide) coordinates to two different Zn^II ions, one via the thione group and the other via a ring N atom, with one Zn^II 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.