Synthesis And Peroperties Of Porphyrin-Schiff Base

Porphyrin compounds play an extremely important role in many research and application areas, such as molecular wires, molecular switches, molecular rectifiers, and luminescent materials. Porphyrin compounds, with unique characteristics of photochemistry, and electrochemistry, are excellent candidates for preparing linear molecular materials. Meanwhile, Schiff bases are imines or substituted imine derivatives with-C=N-groups and strongly coordinating ability. Formation of-C=N-bond as brigde group, molecules with conjugating configuration can be easily desgined and conveniently synthesized. In this thesis, a macrocyclic compounds,5-(4-aminophenyl)-10,15,20-triphenyl porphyrin (APTPP), was successfully prepared, and then a conjugated molecular wire based on APTPP with-C=N-brigde was efficiently synthesized. This peripheral modification around porphyrin ring caused obvious change in electron configuration, and therefore the characters of UV-Vis, photoluminuent and even EPR were examined in detail.This thesis focused on the synthesis and characterization of porphyrin-Schiff base with conjugated configuration. It was divided into four parts:In the first chapter, we described recent research situations related to porphyrin derivatives. Close attention was paid to the synthesis and application about metalloporphyrins. In the second chapter mainly discussesed the synthesis of5-(4-aminophenyl)-10,15,20-triphenyl porphyrin and its characterization, including determinations of UV-Vis, IR, fluorescent spectrometry,1H-NMR. The influence of the ratio between NaNO2and TPP on the yield of5-(4-aminophenyl)-10,15,20-triphenyl porphyrin was summarized. When the mole ratio is1.2:1, the yield of purpose porphyrin can reached as high as80%. In the third chapter, we introdued the brigde molecule’s preparation. A series of Schiff bases with aldehyde terminal groups were successfully synthesized under microwave irradiation. The influences of microwave irradiation time, temperature, ratio of reagents on the yield of Schiff base were examined, and finaly the reaction conditions were optimized as: T=80℃, microwave time:25min, the ratio of reagents:1.2:1. During a single synthetic circle, Schiff base with yield95.4%was obtained. In the forth chapter, we introduced synthesis of two kinds porphyrin-Schiff base molecular wires. Both of them were characterized by UV-Vis, IR, fluorescent spectrometry, and1HNMR. Irradiation under ultraviolet light (365nm) resulted in conversion between cis-and trans-configurations for these porphyrin wires, and these changes in electron configurations were well examined by in situ determinations of UV-Vis and electron paramagnetic resonance. The molecular wires of diporphyrin-schiff base provided red emitting characters owing to its high delocalized π electron, and therefore they were selected as candidate for design and preparation of the linear molecular wires applying in the fields of electron or photon transmission, and charge separation.