Synthesis And Self-Assembly Of Triblock Linear And V-shaped Rigid-flexible Amphiphilic Molecules

Elaborate design of molecules and creation of supramolecular nano-structure with clear form and size,offers a new strategy for development of molecular electronics,biomimetic chemistry,and materials science.Among the architecture of molecular self-assembly,?-conjugated amphiphilic molecular assemblies has attracted great attention due to their notable potentials as advanced highly-functionalized materials in area of nanoscience.In this context,amphiphilic rod-coil molecular system has been used for the construction of supramolecular assemblies,and widely applied in biomimetic chemistry and drug delivery system.The adjustment of their flexible and rigid parts can precisely control the molecular structure of self-assembled nanostructures,such as the length or cross-sectional area of flexible chains and shape or size of the rigid part etc.A variety of ordered supramolecular nanostructures such as spheres,columns,lamellars,vesicles and fibers have been constructed in bulk and aqueous solutions.Among them,the shape of the rigid portion has a significant effect on the intermolecular forces and arrangement.Different shapes of rigid-flexible block molecules were synthesized and their assembly properties were studied,such as T-type,H-type,O-type,n-type,dumbbell type etc.In the bulk,self-assembly forms 2-D columnar,3-D hexagonal close packing,body-centered tetragonal,etc.;New nanostructures such as nanotubes,coiled nanobelts,and nano cages are formed in aqueous solution,and applied to drug release,nano reactors,cell proliferation control,carbohydrate enrichment and separation,and other fields.In this paper,linear and V-type amphiphilic molecules were designed and synthesized,and the length,cross-sectional area of the flexible chain,the influence of the methyl side chain on its self-assembly structure and the self-assembly structure in aqueous solution were studied.The influence of the hydrogen bond interaction introduced by the center of the rigid part on its self-assembly was further studied in the molecule.Using Suzuki,Sonogashira and other reactions to synthesize(1)Linking five biphenyls with ether bond as rod block,then linking different flexible chains to form rod-coil block copolymers(2)A series of bent-shaped molecules,consisting of dibenzo[a,c]phenazine and phenyl groups connected together as a rod segment and poly(ethylene oxide)(PEO)with a degree of polymerization(DP)of 6 as the coil segment,were synthesized.And we use DSC,XRD,TEM,AFM and other means to test the morphology of the target molecule.The research explores the intrinsic link between the self-assembled structure of amphiphilic molecules and the molecular structure,and the influence of the tiny changes in the molecular structure on the molecular assembly structure.