An easy reversible switching of the electronic ground state in a pentacoordinated copper(II) complex is reported for the first time. The simple protonation of a carboxylic group in a Cu(II) complex with a {dx(2)-y(2)}(1) electronic configuration leads to a flip of the ground electronic configuration from {dx(2)-y(2)}(1) to {dz(2)}(1) in the metal ion.
A methylene-bridged 1-hydroxybenzotriazole derived ligand L [L = 1, 3-bis(benzotriazol-1-yl)-1,3-dioxapropane] has been synthesized and characterized by spectroscopic and structural methods. Reaction of L with two different copper(II) halides [CuX(2); X = Br, Cl] in an identical condition yields two different compounds of similar compositions, {[Cu(μ-Br)(Br)(μ-L)](2)}(n)·2nH(2)O (1) and {[Cu(μ-Cl)(Cl)(μ-L)](2)}(n)·2nH(2)O (2), both being characterized by various physicochemical techniques. Single crystal X-ray studies reveal that they appear as 2D coordination polymers with similar bridging fashion of L. Low temperature magnetic susceptibility measurements reveal antiferromagnetic and ferromagnetic behaviors for 1 and 2 with magnetic coupling constants J = -15.2 and +1.7 cm(-1), which are in a reasonable agreement with their calculated values (J = -9.79 and +0.68 cm(-1) respectively, for 1 and 2). The role of bridging halides in the structure and magnetic properties of the complexes are investigated, and a possible magneto-structural correlation has been established. Influence of spin density of bridging halides on the magnitude of coupling constants has been discussed with the help of density functional theory (DFT) calculations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.