Synthesis and properties of copper(II) complexes with a chiral dioxatetraazamacrocyclic ligand based on a natural monoterpene, (+)-3-carene

The copper(II) compounds [CuL](NO3)(2) center dot H2O (I), [CuL](ClO4)(2) center dot H2O (II), CuLCl2 center dot 3H(2)O (III), and CuLBr2 center dot 4H(2)O (IV), where L is a chiral dioxatetraazamacrocyclic ligand based on the natural monoterpene (+)-3-carene, have been synthesized. According to IR and EPR spectroscopy, L acts as a tetradentate chelating ligand coordinated through the N atoms of the NH and C=N groups. The NO3- anions in I and the ClO4- anions in II are outer-sphere. I and II have a planar coordination core CuN4, III has a CuN4ClO coordination core, and IV has a CuN4Br2 coordination core.