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

Tetrazolic acid, CN 4 H, has similar acidity to carboxylic acid group, COOH. 1‐(4‐Hydroxyphenyl)‐5‐mercaptotetrazole (H 2 L) 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 (H 2 O) 2 ( 1 ), [Mn(HL) 2 (H 2 O) 4 ]·2H 2 O ( 2 ), Mn(HL) 2 (Phen) 2 ( 3 ), and [Zn(HL) 2 (Phen) 2 ]·0.5H 2 O·1.5CH 3 OH ( 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.