Solvent-Induced Self-Assembly of Naphthalenediimide Conjugated to Tetraphenylethene through D-and L-Alanine

摘要

Herein,the synthesis and supramolecular self-assembly of naphthalenediimide(NDI)-tetraphenylethene(TPE)conjugates with l-alanine(coded as: 1)and d-alanine(coded as: 2)was investigated.The pair stereoisomer molecules were designed to undergo self-assembly under solvophobic effects.Mixtures of THF–water was used to fine tune the solvophobic effect leading to microbelt for both 1 and 2 in 40% v/v of THF in H2O,while microbelt and particulate microsphere supramolecular structures were observed in 20%,v/v THF in H2O.When 10% THF in H2O was employed derivative 1 produces belt-like structures,however,2 produces microsphere.Less uniformly defined microstructure morphologies of 1 and 2 were formed in THF/hexane and DCM/hexane.The solvophobic effect on self-assembly further evidenced using UV/Vis,fluorescence,circular dichroism,X-ray diffraction(XRD)spectroscopies.DLS used to evaluate formation of assembly in solution,DFT(density functional theory)and TD-DFT(time dependent density functional theory)molecular modelling support the hypothesis.Scanning electron microscopy used to visualise formation of supramolecular self-assembled nano-and microstructures.