ABSTRACT: The title complex, [CuII(ClO4)(mesoPYBP)](ClO4) {PYBP = 1,1'-bis-[(pyridin-2-yl)meth-yl]-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 tetra-dentate amino-pyridine 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⋯O hydrogen bonds with the PYBP ligand and balance the total charge of the complex salt. The two crystallogra