Studies On The Synthesis And Properties Of Schiff Base Bonded Porphyrins

Porphyrin compound as light-emitting material is widely used as organic thinfilm electroluminescent devices. It has strong fluorescence properties, and theemission wavelength is in the red light district, so it is widely used in RedLight-Emitting Diodes status of research and applications. The fluorescencequantum yield is not very high, if we use porphyrin alonely as a red material. Themodification of the porphyrin can provide energy to the porphyin. The transferationof energy will be modified as the groups transfer energy to the porphyrin in thespecific wavelength of light excitation, which enhancing the luminescence propertiesof porphyrin. The Schiff base which is known as imine or imine substituents is aclass of organic compound containing C=N group. It has been favored byresearchers because of its functional group has special properties, such as, a goodchromophore, mechanical stability and electrical conductivity. Synthesis of Schiffbase is relatively easy, by changing the different amines and aldehydes and ketonesto develop the structure of volatile compounds. Combined the porphyrin and Schiffbase, it may be realized the energy transferation from Schiff base to the porphyrinwhich improved the luminescent properties of porphyrin. Based on thisconsideration of the porphyrin and the Schiff base, we continued the studies ofsynthesis and properties research of Shiff base porphyrin. The main content is listedas follows:1. Summarized the synthesis and application of porphyrin in OrganicLight-Emitting aspects of optical memory, photoconductive materials, andintroduced the research progress of the Schiff base.2. Designed and synthesized three kinds of Schiff base porphyrins. Aftersynthesized a class of meso-hydroxyl porphyrin,4-hydroxyphenylehyde wasconnected to which by dibromoalkane, and then reacted with amine to get the targetmolecule Shiff base bonded porphyrins. The structures were characterized by1HNMR, mass spectrometry.3. Some problems during the synthesis of target compounds and theirintermediates are discussed for the purpose of improving their synthesis.4. Compared the synthesized Shiff base bonded porphyrin compounds with thetetraphenylporphyrin in the spectroscopic properties, we found that the synthesized Shiff base bonded porphyrins had better fluorescence emission in the red lightdistrict, and its UV spectra removed to red shift. Their quantum yield (0.18-0.22)compared with tetraphenylporphyrin (0.11) has been greatly improved and increasedwith increasing number of Schiff base.5. Chem3D was explored for the calculation of the structure energies ofsynthesized Shiff base bonded porphyrins to explain the changement in spectralproperties of the synthesized compounds.