Preparation And Characterization Of Chiral Semiconductor Materials At Nanoscale

The combination of conductive materials and chiral supramolecular materials is not a simple liner addition,but a concept like 1+1>2.The combination of these two concepts not only expands the research of conductive polymer materials,but also gives new function and application to chiral supramolecular structures.In traditional chiral supramolecular structures(such as DNA molecules,protein molecules,etc.),the molecules are generally insulators or semiconductors which have poor conductivity.Among the chiral supramolecular structures synthesized in this paper,we particularly emphasized that they have a relatively good electrical conductivity,which made they can be used in molecular devices.In addition,they also have a foreseeable application in the fields of chiral separation or bio-catalysis,as the chiral supramolecular structures usually have a good biocompatibility.In this paper,we synthesized several molecules with both chirality and conductivity mainly through the method named small-molecule-induced,then conducted a series of performance tests on their molecular devices.They included chiral small molecule conductive materials and chiral polymer conductive material.We synthesized two kinds of chiral small molecule,namely phthalocyanine copper(II)molecule with chiral branch and structure-regular thiophene-[3,2-b]-thiophene molecule with chiral branch.The chiral unit we selected is the simplest model,2-methyl-1-butanol,which has an ethyl,a methyl,a hydrogen atom,and an adjustable group attached to the central carbon atom(?-carbon atom).We used(R-/S-)2-methyl-1-butanol as the reactant and attached the chiral unit to the branch of phthalocyanine copper(?)or the side chain of thiophene-[3,2-b]-thiophene.Each of them has a relatively large conjugate plane in the molecule,which promoted the forming of supramolecular structures by ?-? stacking interactions between molecules.The chiral conductive polymer materials mainly studied in the paper,are polyaniline nanofibers doped with single-rotation camphor sulfonic acid and polyaniline nanofibers doped with achiral p-toluene sulfonic acid.We used a classic method to dope polyaniline with chiral camphor sulfonic acids and made the nanofibers into an electrical device for the test of conductivity and hysteresis resistance effect.We also prepared non-helical polyaniline nanofibers with p-toluene-sulfonic acid,used as comparison.In the end of this part,we introduced the synthesis and preparation of regular-structured polythiophene nanostructures which concerned as an unfinished work.The synthetic route and preliminary synthesis work are mentioned in this paper.