Studies On Design,Synthesis And Properties Of Heterocyclic Fused Porphyrins

Porphyrin an 18? aromatic macrocycle,is a class of four pyrrolyl groups that are bridged by four methine groups.Introduction electron-donating groups at the peripheryal positions of prophyrin,it could obtain?-extended porphyrinoids which will exhibit efficient electron-transfer,large two photon absorptions and light harvesting characteristics.These modified porphyrins have applications in a variety of fields since their research concerns areas ranging from biology,opticas,electrochemistry.About studying fused an aromatic hydrocarbon or aromatic heterocycle directly onto the porphyrin periphery,?,??-fused quinoxalinoporphyrins and their analogues have attracted a great deal of attention from chemists and materials scientists.Owing to the photophysical properties of these porphyrins,which served as molecular wires,electron donor–acceptor,sensitizers in dye sensitized solar cells.Crossley et al attempted the synthesis of a series of?,?'-heterocyclic fused porphyrins were achieved by condensation of porphyrin-2,3-diones with aromatic amines.However the strategy had some shortages,such as the raw materials were difficult to synthesize,the routes were long and its yields were too low.Therefore,it is challenging and important to find a simple and efficient synthetic method for achieving similar compounds.With these backgrounds,a series of heterocyclic fused porphyrin compounds were designed and synthesized via C-N coupling reactions by palladium-catalyzed.The detailed studies are listed as follows:(1)A brief description of the construction of fused aromatic heterocycle directly onto the porphyrin periphery in recent decades.(2)A series of aromatic amines and brominated porphyrins were synthesized in high yield.(3)The systhesis of diverse?,?'-heterocyclic fused porphyrins by palladium-catalyzed C-N coupling reactions of brominated porphyrins with planar aryl ortho-diamine subsequent oxidation with manganese dioxide.The structures of these compounds were characterized by ¹H NMR spectroscopy and corresponding structures of these compounds were unambiguously elucidated by X-ray diffraction analysis.(4)Based on the above studies,we had expanded our aromatic amines and turned our attention to aromatic amines with three-dimensional rigid structures,namely,triptylenamides.A class of triptycene-fused three-dimensional porphyrins were obtained by Pd-catalyzed C-N coupling reaction of bromoporphyrin with triptycediamine,triptycene tetraamines and hexahydrochloride adduct of hexaaminotriptycene.The structures of these compounds were characterized by ¹H NMR spectroscopy and corresponding structures of these compounds were unambiguously elucidated by X-ray diffraction analysis.The 10Zn displays a propeller structure,the dihedral angles between the quinoxaline units that linked with the porphyrin are117.38(12)°,119.85(12)°,122.74(13)°.Respectively,with increasing the number of fused porphyrins yet the UV/Vis absorption wavelength without move to the long-wave direction,due to the rigid structure of triptycene,which makes the three-part conjugated system.However,with increasing the number of fused porphyrins,a molar absorptivity of the Soret band enhanced.10Zn displays a molar absorptivity of 530329 M^-1cm^-1 at 449 nm.