Abnormal change of triazole-pyridyl dihedral angle in a Co(II) complex with asymmetrical substituted triaryltriazoles

A cobalt(II) complex, trans-[CoL ₂(H ₂O) ₂](ClO ₄) ₂·2C ₂H ₅OH, (L=3-(p-methoxyphenyl)-4-(p-bromophenyl)-5 -(2-pyridyl)-1,2,4-triazole), was synthesized and characterized by FT-IR, ESI-MS, TGA and X-ray crystallography. The complex crystallizes in monoclinic system with space group P2 ₁/n, a=0.876 3(5) nm, b=3.384 4(18) nm, c= 0.920 3(5) nm, β=102.961(8)°, E=2.660(2) nm ³, Z=2 with final R=0.064 4. The cobalt atom lies in a distorted octahedral environment with two water molecules in the trans positions. The ligand L coordinates via one triazole nitrogen and pyridine nitrogen atom. The triazole-pyridyl dihedral angle in the complex is larger than that in the free L ligand. The TG analysis shows that the complex is stable below 345 °C. CCDC: 859546.