A phthalocyanine (Pc)-analogue containing two pyridine units is dimerized v
ia two pyridine-Pd-pyridine bridges to form a novel type of planar or nearl
y planar Pc dimer. Because of the structural constraint in the constituent
monomer. this dimer has a rhombic-shaped square in its center, which has no
t been attained previously in porphyrin-based supramolecules. (C) 2001 Else
vier Science Ltd. All rights reserved.