Coexistence of molecular Pd6 triangle and Pd8 square self-assembled from naphthyl-dipyrazole with di-palladium motifs

Two novel nanosized bipyrazolate-bridged metallo-macrocycles with dipalladium(II,II) corners, {[(bpy)Pd]8L4}(NO3)8 and {[(bpy)Pd]6L3}(NO3)6 [L = 1, 4-di(3′,5′-dimethyl-1H-pyrazolyl-4yl)naphthalene] have been synthesized through a directed self-assembly approach that involves spontaneous deprotonation of the 1H-bipyrazolyl ligand in aqueous solution. These crown-shaped complexes with deep cavities potentially served as the host to solvent molecules and anions. Such metallo-macrocyclic structures have been characterized by single-crystal X-ray diffraction analysis, elemental analysis, 1H and 13CNMR, high resolution electrospray ionization mass spectrometry, UV–visible spectroscopy, and luminescence spectroscopy.