Study On The Synthesis And Properties Of Doped Earring Porphyrins And Its Oligomers

Porphyrin metal complexes generally employ the inner cavity as the coordination site.Previously,Song group synthesized ?-? tripyrrin-bridged“earrings”porphyrins in high yield through Suzuki-Miyaura cross coupling reactions.These earring porphyrins have multiple cavities,and two or three metal ions can be complexed at the same time.Compared with porphyrins,the red shift of absorption and the decrease of HOMO-LUMO gap appeared in the earring porphyrins.The metal complexation will be accompanied by the change of structures,leading the above changes to be more obvious.A series of benzene,pyridine doped earring porphyrins and their oligomers were prepared by Suzuki-Miyaura cross coupling reactions.Structures and photophysical properties of earring porphyrins were investigated.The key studies were listed below.(1)According to literatures,1,2,4,5-tetraborylated benzene was coupled with an excess amount 2,6-dibromopyridine to obtain1,2,4,5-tetra(6-bromopyrid-yl)benzene;A series of?-borylated pyrrole derivatives 4b,5b,6b were achieved by borations of2,6-Bis(pyrrol-2-yl)pyridine,1,3-Bis(pyrrol-2-yl)benzene and 1,2,4,5-tetra(pyrrol-2-yl)benzene,respectively.These compounds were characterized by ~1H NMR.(2)Pyridine-benzene doped earring porphyrins and thiophene-pyrrole-bridged cyclic porphyrin dimer were obtained by 1Br,2Br,3Br reacting with 1,3-diborylbenzene,?-diborylpyrrole,respectively.Pyridine doped earring porphyrins and pyrrole-benzene bridged cyclic porphyrin dimer were achieved through Suzuki-Miyaura reaction of?-brominated porphyrin and?-borylated pyrrole derivatives 4b or 5b.Metalation of the these doped earring porphyrins with palladium(II)acetate or copper(II)acetate to provide corresponding Pd(II),Cu(III)complexes,respectively.The explicit structures of earring porphyrins complexes were confirmed by single-crystal X-ray diffraction analysis.It was proved that the cavity of pyridine doped earring porphyrins can be used to stabilize higher oxidized metal ions to form stable organometallic compounds.(3)A benzene-doped earring porphyrin dimer was prepared by Suzuki-Miyaura coupling reaction;Pyridine-benzene-doped earring porphyrin dimer was synthesized by Suzuki-Miyaura coupling reaction between 7Br andb,b'-diboryl porphyrin.Benzene-doped earring porphyrin dimer 6Ni was confirmed by crystal X-ray diffraction analysis.The photophysical properties of these earring porphyrins were discussed.The absorption of these earring porphyrins derivatives extends into the near-infrared spectral region,and these features have potential applications in optical devices in the near-infrared region.