Meso-Substituent Effects on Redox Properties of the 5,10-Porphodimethene-Type P,S,N₂-Hybrid Calixphyrins and Their Metal Complexes

The 5,10-porphodimethene-type P,S,N2-hybrid calixphyrins bearing p-methoxyphenyl or p-(trifluoromethyl)phenyl groups at the sp2-hybridized meso carbons and their palladium(II) and rhodium(I) complexes were prepared and characterized. The electronic effects of the meso-aryl substituents on the redox properties of the π-conjugated subunits were evaluated for both the free bases and the palladium complexes, and the hemilabile nature of the P,S,N2-calixphyrin platforms in the rhodium complexes was revealed.