Structural and Magnetic Properties of the {Cr(pybd)3[Cu(cyclen)]2}(BF4)4 Heteronuclear Complex

Heterotopic ligands containing chemically different binding centers are appealing candidates for obtaining heteronuclear metal complexes. By exploiting this strategy, it is possible to introduce paramagnetic characterized by specific anisotropic magnetic properties that make them distinguishable when weakly magnetically coupled. This molecular approach has great potential yield multi-spin adducts capable of mimicking logical architectures necessary quantum information processing (QIP), i.e., logic gates. A route including a single-ion center within finite-sized heterometallic compound uses the asymmetric (1-pyridyl)-butane-1,3-dione (pybd) ligand reported in literature Cr3+−Cu2+ metallo-cages. To avoid formation cages, we adopted cyclen (1,4,7,10-tetraazacyclododecane) as “capping” agent Cu2+ ions. We report here structural and characterization unprecedented adduct {Cr(pybd)3[Cu(cyclen)]2}(BF4)4, whose structure central Cr3+ ion distorted octahedral coordination environment two peripheral ions with square-pyramidal geometries. As highlighted Continuous Wave Electron Paramagnetic Resonance (EPR) spectroscopy Direct Current (DC) magnetometry measurements, shows negligible intramolecular couplings, maintains characteristic EPR signals moieties diluted frozen solutions.