The first phthalocyanine-based dimer formed by two pyridine-Pd-pyridine bridges

A phthalocyanine (Pc)-analogue containing two pyridine units is dimerized via two pyridine-Pd-pyridine bridges to form a novel type of planar or nearly planar Pc dimer. Because of the structural constraint in the constituent monomer, this dimer has a rhombic-shaped square in its center, which has not been attained previously in porphyrin-based supramolecules.