Importance of chelate-chelate stacking interactions in crystal structures of square pyramidal copper(II) complexes with two distinct chelating bidentate ligands

摘要

Two square pyramidal copper(II) complexes, [Cu(bzan)(mdap)(OClO3)] (1) and [Cu(bzan)(dmdap)(OClO3)] (2) [Hbzan = 1-benzoylacetone, mdap = N-methyl-1,3-diaminopropane, dmdap = N,N-dimethyl-1,3-diaminopropane], have been prepared and characterized. Single crystal X-ray diffraction studies have confirmed their structures. Both complexes form supramolecular dimers via pi/pi interactions between the chelate rings. The energies associated with pi-stacking interactions to form self-assembled dimers have been computed using DFT calculations. The energy associated with N, C-H/pi contributions have also been evaluated. Bader's theory of "atoms in molecules" (AIM) was also used to further describe the non-covalent pi-stacking and N, C-H/pi interactions. (C) 2015 Elsevier B.V. All rights reserved.