Synthesis and Crystal Structures of Four Metal(II) Complexes with 1‐(4‐Hydroxyphenyl)‐5‐mercaptotetrazole Ligand

Tetrazolic acid, CN4H, has similar acidity to carboxylic acid group, COOH. 1‐(4‐Hydroxyphenyl)‐5‐mercaptotetrazole (H2L) can act as a monodentate (S or N) or a bidentate (N, N or N, S) ligand, forming coordination compounds with metal ions. Four new M(II) complexes with HL− ligands, Co(HL)2(Py)2(H2O)2 (1), [Mn(HL)2(H2O)4]·2H2O (2), Mn(HL)2(Phen)2 (3), and [Zn(HL)2(Phen)2]·0.5H2O·1.5CH3OH (4) have been synthesized and structurally determined by X‐ray structure analyses. Among these complexes, the M(II) centers are all six‐coordinated in an octahedral coordination geometry, and HL− ligands bond to M(II) centers via nitrogen atoms in 1 and 2, while via sulfur atoms in 3 and 4, respectively.