Abstract
A variety of phthalocyanine (Pc) dimers have been reported including both double-decker and co-planar type compounds and their spectroscopic and electrochemical properties have been shown to differ significantly from those of the corresponding monomers. However, control of three-dimensional arrangement of Pc units in dimer systems has been rather limited although such Pc dimers and oligomers are potentially useful as novel Pc-based functional materials.
In order to control three-dimensional arrangement of Pc units in dimer systems, we used a biphenyl group as a linker unit, which led to novel three-dimensionally controlled dimers molecule bearing a propeller-like conformation of Pc units due to the dihedral angle of the biphenyl unit.
The target Pc dimers were synthesized by a mixed macrocyclization reaction of a biphenyl linked phthalonitrile which was prepared by reacting of 4-brono-5-nitrophthalonitrile with 2,2',6,6'-tetrahydroxybiphenyl and the absolute structure was determined by chiral resolution and X-ray crystallography. No racemization was occurred during the reactions, and the obtained chiral dimers exhibit strong Cotton effect with mirror-imaged circular dichroism (CD) signals.
In this presentation, we report synthesis and spectroscopic properties of the Pc dimers including magnetic circular dichroism (MCD) spectra and theoretical calculations.
