Research On LB Films And Organogels Composed Of Some Functional Molecules

Chiral supramolecular is a special supramolecular with chirality property and it has many applications in life science,pharmic and material science.LB Langmuir-Blodgett(LB) technique and organogel are important methods to build up supramolecular chirality on planar interface and three-dimensional, respectively.We have synthesized the metalloporphyrins(CuTPPA3,CuTPPA3-A, ZnTPPA3,CuTPPA1,ZnTPPA1) with long hydrophobic chains and hydrophilic substituted groups.The air/water interfacial aggregation behavior and supramolecular chirality of three molecules were investigated.All the porphyrins show good spreading behavior on water surface.The transferred films were characterized by a variety of methods including UV-visible spectroscopy,circular dichroism spectroscopy,FTIR spectroscopy,atomic force microscopy(AFM) and scanning electron microscope(SEM) measurements.The zinc derivate of the porphyrin aggregate into incompact assemblies at air/water interface,and can not form overcrowded packing with supramolecular chirality.On the contrary,the copper derivative of TPPA3 can form tight aggregation with semi-helical sense morphologies and strong cotton effect at high pressure.However,once the ester group of copper porphyrin was hydrolyzed into the carboxyl acid,the intensity of the CD signal from the LS films decrease largely.A possible mechanism for the subtle relationship between supramolecular chirality and molecular structures has been proposed.Beside on the planar interface,we investigated the relationship of functional molecular structures and bulding up supramolecular chirality,and building up supramolecular chirality from achiral molecules.We also investigated the relationship between the doped small molecules and induced circular dichroism, which is inducing achiral molecules to build up supramolecular chirality with the chiral molecules and chirality magnify.The doping of some Schiff base compounds in organogels has been investigated.It was found that although these Schiff bases could not form organogels themselves,they can gel by mixing with an organogelator,N, N'-bisoctadecyl L-Boc-glutamic-diamide,which formed transparent organogels in DMSO or toluene.The enhancement of doping schiff bases fluorescence in the organogel was observed,in comparison with that of the corresponding solution. Furthermore,in the DMSO organogel,the induced chirality was obtained from the doping Schiff base with long alkyl chain.On the other hand,the schiff bases without long alkyl chain cannot form supramolecular chiral assemblies in organogel.It was suggested that through the gel formation,the chirality of the gelator could be transferred to the schiff base through hydrophobic interaction among the long alkyl chains.