Supramolecular Assemblies Of Benzimidazole And Porphyrin Derivatives Controlled By Colloid And Interface Technology And Their Properties

The assembly and performances of functional organic materials controlled in terms of colloid and interface protocols,such as air/water interfacial assembly and surfactant-assisted nanofabrication using water/oil systems as medium,have attracted increasing research widely attention.Based on these methods,The supramolecular assembly occurred at the air/water interface and oil/water systems were systematically investigated for benzimidazole and porphyrin derivatives,respectively.We found that a novel structure-activity correlation within the functional aggregations.(1)Ordered ultra-thin films of 2-(?-naphthyl)benzimidazole(?-NpBz)can be obtained through Langmuir-Blodgett(LB)technology at the air/water interface,it is found that the resulted supramolecular assemblies always exhibited as stochastic chiroptical properties,where levorotatory or dextrorotatory chiral supramolecular assemblies present themselves indeterminately.Meanwhile,the properties of supramolecular assembly of L-or D-octadecanoyl-histidine methyl ester(L-or D-C18His)in Langmuir-Schaefer(LS)films were investigated through the air/water interface and we revealed the reason for their stable film formation and the mechanism of their supramolecular optically active.Also the LS film of the mixed system of L-or D-C18 His and ?-NpBz can be obtained at the air/water interface.We have showed that the optically active properties of the LS films of the supramolecular assemblies of an achrial molecular ?-NpBz,which had been previously proved to form chiral supramolecular assemblies through the air/water interfical organization,could be controlled to some extent by a chiral dopant,L-or D-C18 His.When the molecular ratio between the L-or D-C18 His and ?-NpBz was 1:30,the LS films of the mixed system showed monosignated induced circular dichroism(ICD)absorption,which seemed follow the chirality of the chiral component employed.A plausible explanation based on the hydrogen bond induced hybrid supramolecular assemblies of the chiral and achiral components have been proposed for the interesting results.The strategy provided us a significant ideal to control the optically activities of the supramolecular assemblies built up by the air/water interfacial organization of achiral building blocks.(2)The assemblies via air/water interface are subject to the general application of the materials because of solid substrates,then how to control the free-standing assemblies has received much attention in the field of catalyst.With the assist of surfactant CTAB,we report herein that porphyrin nanostructures of near-spherical and 1D morphology could be controllably produced.It is found that show that a smooth nanometer spherical morphology could be produced after dropping an ZnTPyP solution into an aqueous solution of CTAB surfactant under stirring 15 min,while these initially formed near-spherical species could automatically evolve into 1D nanorods simply by extending the aging time until 20 d under ambient conditions.Interestingly,we have observed that 1D nanorods have transformed into nanotube-like structure after the visible light irradiation for 120 min without the substrates.The results of neutral red degradation show that nanorods and nanotubes can exhibit excellent photocatalytic performance,which is closely related to the anisotropic 1D morphology.These research phenomena provides an innovative direction for the controlling porphyrin nanostructures and the development of high-performance photocatalysts.