Syntheses And Characterization Of Unprecedentedβ, β′-Linked Porphyrin-Chlorin Heterodimers And Calix[4]phyrins

Porphyrin dimers (including heterodimers) have been attracting considerableattention as models in photosynthetic systems, molecular devices, catalytic reactions,energy transfer and electron transfer. In these systems, the porphyrin units are directlylinked by meso-meso，β-β or meso-β positions. Among them, fewer reports are on β-βand meso-β linked porphyrin dimers. It is because that these porphyrins are typicallysynthesized through multi-step coupling reactions which inevitably cause somesynthetic difficulties. There are even fewer reports on porphyrin-chlorin heterodimers.Porphodimethenes (PDM) are a class of calix[4]phyrins that lie at the structuralcrossroads between porphyrins and calixpyrroles. Because of their unique structures andpotential utility in supramolecular cation and anion recognition applications, they arebeginning to receive increasing attention. So in this thesis, it covers β, β′-linkedporphyrin-chlorin heterodimers and porphodimethenes two parts.Firstly, the porphyrin-chlorin heterodimers,1a or1b, has been synthesized by aone-pot reaction. The compounds are characterized by1H NMR, mass spectroscopy,X-ray crystallography, cyclic voltammetry, UV-vis and fluorescence spectroscopy, etc.The crystal structures show that1a is a novel porphyrin-chlroin heterodimer, suchheterodimer is unique among porphyrinoid in that the dimeric linkage features a directCβ–Cβ bond between one porphyrin and one chlorin moiety, and the porphyrin moiety isa tetraphenylporphyrin unit, while the chlorin moiety is a2,3-disubstituted chlorin withan exocyclic ring unit. At same time, the porphyrins with an exocyclic ring (2a and2b)are also obtained, which are more similar with the chlorin moiety of the heterodimers,and these species have been characterized. Secondly, the four porphodimethene isomers,5,15-disubsitituted (PDM-1a and1b)and5,10-disubstituted (PDM-2a and2b), have been synthesized in a one-pot reaction.The isomers have been characterized by1H NMR, mass spectroscopy, X-raycrystallography and UV-vis spectroscopy, etc.