1,8-萘酰亚胺衍生物的合成、表征及电存储性能

摘要

本文以三苯胺结构作为电子给体,与三种接有不同吸电子基团的1,8-萘酐反应合成了具有电子给-受体结构的N-(4-三苯胺)-1,8-萘酰亚胺(NA-ATPA)、N-(4-三苯胺)-(4-氰基)-1,8-萘酰亚胺(NA(CN)-ATPA)和N-(4-三苯胺)-(4-硝基)-1,8-萘酰亚胺(NA(NO2)-ATPA),并对它们的结构进行了表征.利用紫外可见光谱、荧光发射光谱和循环伏安法对产物的光物理性能和电化学性能进行了测试,并测试了其存储行为,结果显示NA-ATPA表现出易失的静态随机存储行为(SRAM),NACN-ATPA表现出非易失的闪存型存储(Flash),NA(NO2)-ATPA表现出非易失只读型存储(WORM).三种萘酰亚胺对存储行为中高导态的维持能力逐渐增强,其原因是引入的吸电子基团的吸电子性越强,其LUMO值和能隙值降低的越多,越利于电荷转移,形成更稳定的电荷转移络合物.另外,本文还对原料和产物的电子结构、分子轨道和能级进行了分子模拟计算,研究了三种化合物基态和激发态的差别,并对其电子转移过程进行了理论分析.%In order to clarify the influence of different electron-withdrawing groups on the electronic structures and memory properties of naphthalimides,three 1,8-naphthalimides,namely N-(4-triphenylamino)-1,8-naphthalimide (NA-ATPA),N-(4-triphenylamino)-(4-cyano)-1,8-naphthalimide (NA(CN)-ATPA) and N-(4-triphenylamine)-(4-nitro)-1,8-naphthalimide (NA(NO2)-ATPA),were designed and synthesized using triphenylamine (TPA) as the electron donor and 1,8-naphthalene dianhydride containing different electron-withdrawing moieties (-H,-CN,-NO2) as the electron acceptor.The photophysical properties and electrochemical characteristics of the compounds were investigated by ultraviolet-visible spectroscopy (UV-Vis),fluorescence spectroscopy (FL) and cyclic voltammetry (CyV).The synthesized products were applied as the active layer in sandwich devices,whose memory characteristics were tested.NA-ATPA shows volatile static random access memory (SRAM) behavior,while NACN-ATPA and NANO2-ATPA show nonvolatile flash and write-once read-many times memory (VVORM) behavior,respectively.Experimental results indicated that the synthesized compounds possessed small energy gaps and wide absorption ranges.The introduction of electron-withdrawing groups on the 4-position of the 1,8-naphthalimides reduced the LUMO energy level and the energy gap,leading to improved stability of the charge-transfer state and volatile-to-nonvolatile memory transfer.To elucidate the switching mechanism,molecular simulation results,including molecular orbitals,energy levels,optimized geometries,and Mulliken charge populations,were discussed.