{1,1′-Bis[(pyridin-2-yl)methyl]-2,2′-bipiperidyl}(perchlorato)copper(II) perchlorate

The title complex, [Cu-II(ClO4)(mesoPYBP)](ClO4) {PYBP = 1,1'-bis[(pyridin-2-yl)methyl]-2,2'-bipiperidyl, C22H30N4}, was prepared and found to crystallize with two crystallographically independent complex salt moieties. The metal atoms of the cations adopt a pseudo-square-pyramidal coordination geometry, where the tetradentate aminopyridine ligands (PYBP) are wrapped around the Cu atoms in the equatorial plane. The Cu-O bonds involving an O atom of the coordinating perchlorate anion are approximately perpendicular to the plane. The two remaining non-coordinating perchlorate anions are involved in several C-H center dot center dot center dot O hydrogen bonds with the PYBP ligand and balance the total charge of the complex salt. The two crystallographically independent moieties are related to each other via a pseudo-translation along the a-axis direction. Exact translational symmetry is broken by (i) a difference in the conformation of one of the piperidine rings, featuring a chair conformation in one of the cations, and a sterically disfavored boat conformation in the other; and (ii) by modulation of the non-coordinating perchlorate anions.