Syntheses, Crystal Structures, and Properties of Two Novel Trinuclear Copper Complexes Constructed by a Tripodal Heptadentate Ligand Containing Three Imidazolate Groups

Abstract

AbstractTwo CuII complexes, {Cu3[(mim)3htren]2}(ClO4)6·2H2O (1) and {Cu3[(mim)3htren]2}(PF6)6·2(CH3CN)·2H2O (2) with the tripodal heptadentate ligand (mim)3htren (= tris{2‐[2‐(1‐methyl)imidazolyl]methylaminoethyl}amine) were synthesized and characterized. In complex 1 and 2, the tripodal ligand (mim)3htren coordinates in a very unusual configuration to the copper atoms, which resulted in trinuclear complexes. In the trinuclear cation, {Cu3[(mim)3htren]2}6+, the middle atom located on a crystallographic inversion center is coordinated in an elongated octahedral arrangement for 1 and coordinated in square‐planar arrangement for 2, respectively, and the other two CuII atoms are coordinated in a distorted square‐pyramid. The results from magnetic data, measured in the temperature range 2.0–300 K, showed that1 and 2 obeyed the Curie–Weiss law with Weiss constants θ = 0.10 and 0.14 K, respectively, and the same Curie constant C = 1.14 K·mo1–1, indicating weak ferromagnetic interactions in the two trinuclearentities.