Abnormal conformation change of an asymmetrical triaryltriazole before and after its coordination

► An asymmetrical triaryltriazole ligand 3-(p-methoxyphenyl)-4-(p-bromophenyl)-5-(2-pyridyl)-1,2,4-triazole. ► Two new mononuclear complexes. ► Their structures were characterized by UV, IR, ESI-MS, and single-crystal X-ray diffraction. ► For the first time, the triazole-pyridyl twist angle in the complexes is larger than that in the free ligand.