Crystal and molecular structure of 2-amino-5-ethyl-1,3,4-thiadiazole and its zinc(II) nitrate complex

The synthesis and X-ray diffraction analysis of the ligand 2-amino-5-ethyl- 1,3,4-thiadiazole (AET) and its zinc(II) nitrate complex are reported. It i s found that the exocyclic amino group of the ligand is coplanar to the het eroring plane, and the ethyl substituent strongly deviates from this plane. The complex [Zn(AET)(3)(H2O)](NO3)(2) is a distorted tetrahedron with thre e nitrogen atoms of the three ligand molecules and the oxygen atom of the w ater molecule in the apices; the nitrate ions are in the outer sphere of th e complex. The ligand coordinates with the central atom is a monodentate ma nner through the endocyclic nitrogen atom located a to the amino group.