A multidentate ligand based on two triazole groups from “click chemistry” and its copper(II) and iron(II) complexes: synthesis, structure, and electrochemistry

A multidentate ligand, namely N,N-bis[[1-(phenylmethyl)-1H-1,2,3-triazol-4-yl]methyl]-2-pyridinemethaneamine (L), was synthesized through a click reaction of N,N-di-2-propyn-1-yl-2-pyridinemethanamine with benzyl azide in the presence of CuI catalyst. Treatment of L with CuCl2 or Fe(NCS)2 gave the complexes [CuLCl2]·EtOH (1) and [FeL(NCS)2]·MeCN (2). Single-crystal X-ray studies show that in 1, the Cu(II) center has slightly distorted square pyramidal geometry resulting from the coordination of one pyridinyl nitrogen atom, one tertiary amine nitrogen atom, one triazole nitrogen atom, and two chloride atoms; in 2, the Fe(II) center has distorted octahedral geometry, coordinated by six nitrogen atoms; two each from NCS− groups and triazole rings, one from a pyridinyl ring, and one from tertiary amine nitrogen. In addition, complexes 1 and 2 were characterized by spectroscopic and electrochemical methods.