三唑和环戊烯苯并菲衍生物盘状液晶分子的电荷传输性质

Charge transport properties of triazole or cyclopentene triphenylene derivative discogen molecules

电荷传输是有机电子材料的重要性质.根据Marcus理论模型,电荷传输为电子-电子相互作用和电子-声子相互作用过程,电子-声子相互作用耦合强度越大,重组能越大,不利于电荷传输.电子-电子相互作用耦合强度越大,电荷传输矩阵元越大,有利于电荷传输.对含1,2,4-三唑、1,2,3-三唑和1,2,3-三氮-2,3环戊烯边链的苯并菲衍生物分子的电荷传输性质进行理论研究.结果表明,含1,2,3-三唑的苯并菲衍生物分子的空穴传输速率和电子传输速率相当,速率常数为2×10^(12)s^(-1).含1,2,4-三唑的苯并菲衍生物分子的空穴传输速率常数为5×10^(12)s^(-1),约为电子传输速率常数的10倍.含1,2,3-三氮-2,3环戊烯的苯并菲衍生物分子的电子传输速率常数为3×10^(12)s^(-1),约为空穴传输速率常数的10倍.目标分子的空穴传输或电子传输速率主要受传输矩阵元的影响,即电子-电子相互作用耦合强度的大小决定传输速率的变化.

Charge transport is one of the most important properties in organic electronic materials.On the basis of Marcus theory,the charge-transfer is the course of electron-electron interaction and electron-phonon interaction,and the greater the electron-phonon interaction coupling strength,the greater the reorganization energy is,which is not conducive to the charge transport.The greater the electron-electron interaction coupling strength,the greater the charge transfer matrix element is,which is beneficial to the charge transport.Charge transport properties of triphenylene derivative discogens molecules with a 1,2,3-triazole,1,2,4-triazole or 1, 2,3-trinitrogen-2,3- cyclopenten side chain are investigated computationally.The results show that the electronic mobility and the hole mobility of 1,2,3-triazole triphenylene derivative are nearly equal,and the rate constant is 2×10^（120 s^（-1）.The hole transfer rate constant of the 1,2,4-triazole triphenylene derivative molecules is 5×10^（120 s^（-1）,which is ten times higer than the electronic transfer rate constant.Triphenylene containing 4,5-dihydro-1,2,3-triazole has better electronic mobility but smaller hole mobility than triphenylene discogens containing 1,2,3-triazole or 1,2,4-triazole,and the electronic mobility is 3×10^（12） s^（-1）,which is equal to ten times of the hole mobility.The hole transfer or electron transfer rate of the target molecules is affected mainly by the transfer matrix element,in other words,electron-electron interaction coupling strength determines the magnitude of mobility rate variation.