1,8-萘酰亚胺类衍生物的结构特性对其吸收和发射光谱影响的密度泛函研究（英文）  

Structural Effect on Absorption and Emission Properties of 1,8-Naphthalimide Derivatives:a DFT Study

作　　者：齐齐[1,2,3] 王育乔[1,2] 孙岳明[1,2] QI Qi WANG Yu-qiao SUN Yue-ming(School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, Nanjing 211189, China Beijing Computational Science Research Center, Beijing 100084, China)

机构地区：[1]东南大学化学化工学院,江苏南京211189 [2]江苏省光电功能材料工程实验室,江苏南京211189 [3]北京计算科学研究中心,北京100084

出　　处：《光谱学与光谱分析》2016年第11期3796-3804,共9页Spectroscopy and Spectral Analysis

基　　金：the National Natural Science Fund Committee(21173042,21201034);support by the Priority Academic Program Development of Jiangsu Higher Education Institutions,Graduate education reform project(XJGKT14-04);Fundamental Research Funds for the Central Universities(2242014k10025,3207045419);the financial assistance from Nanjing science and technology committee(2014-030002);the high performance computation platform of Southeast University

摘　　要：利用B3LYP/6-31G(d)方法优化了一系列N取代1,8-萘酰亚胺类物质的结构,利用含时密度泛函TD-B3LYP/6-31+G(d)方法及C-PCM模式,计算了它们在气相及二氯甲烷溶剂中的吸收和发射光谱。利用计算得出的前线轨道电子云分布及其对应的能级对它们的取代基对电子吸收光谱的影响进行了讨论。结果表明:此种方法计算出的二氯甲烷溶剂中的1,8-萘酰亚胺的吸收光谱与实验光谱比较吻和。取代C=O基团的C=N基团及其成环在吸收光谱和发射光谱中发挥了重要的作用。酰亚胺结构上的改性即C=N基团的引入及在萘环上取代基一方面引入了结构上的不对称性,导致了衍生物的偶极矩的增大;同时结构上的改性扩展了萘酰亚胺共轭结构。4位取代NO_2衍生物从基态到第一激发态的Mulliken原子电荷比5位多一些,这意味着5位取代NO_2衍生物提供了较多的电子。对N(Ph)_2和N(Me)_2衍生物而言,他们4位取代衍生物提供了更多的电荷。前线轨道电子云表明:O=C—N—C=N基团改性扩展和N(Me)_2,N(Ph)_2和NO_2取代基拓展了这类分子的π—π*跃迁范围,从而使得前线轨道能级差降低,它们的吸收和发射光谱也发生了一定程度的红移。对给体取代基而言,它们的4位是电子传输态;对受体取代基NO_2而言,它们的5位是电荷传输态。当NO_2基团与C=O基团在同一侧及当N(Me)_2和N(Ph)_2与在C=N在同一侧时,此类化合物具有较好的传导特性。从化合物1到4,吸收光谱红移了139nm。电荷传输越明显,吸收光谱红移的就越多。O=C—N—C=O的结构改性及其电荷传输机理为今后的萘酰亚胺类物质的分子设计提供了设计理论依据。Using B3LYP/6-31G（d）model,time depended（TD）-B3LYP/6-31＋G（d）method and Conductorlike Polarizable Continuum Model（C-PCM）-TD-B3LYP/6-31＋G（d）method,we calculated the structure and the absorption and emission spectra of a series of N-substituted 1,8-naphthalimides in both gas-phase and dichloromethane.The influence of the substituents on the electronic absorption spectra and their emission spectra has been discussed on their calculated frontier molecular orbitals contour and their energy levels.Results show that their ringsextensionfrom C=N groupandthesubstituentsontheirnaphthalimicringplayanimportant roleintheabsorptionspectraandtheemissionspectraproperties.Modificationof O=C—N—C=O group andthesubstituentsintheirnaphthalimicringsbreaksthestructuralsymmetry.TheMullikenatomiccharges valuesofNO_2 groups from S0 to S1in 4positions are a little greater than the 5-positions,which also mean that the 5position provide more electrons.For MACs of N（Ph）_2and N（Me）_2,the 4position substituents provide more charges than that of 5position.They not only lead to bigger dipole moments,but also extend frontier orbital contour.Frontier orbitals also show that the modification of O=C—N—C=N and the introduction N（Me）_2,N（Ph）_2and NO_2 groups extends theirπ—π＊excitation scope and decreases their energy gap accordingly.Besides,those kinds of molecular design enhance intra molecular charge transfer between substituent and naphthalimic ring.Therefore,redshift are shown in their absorption and emission spectra,which is also verified by calculated results.Their absorption and emission spectra in solvent redshift compared with their gas spectra.For the NO_2 derivatives,the charge transfer state is in the 5position substituent compounds.For donor substituents,charge transfer state lies in their 4position compounds.When the C=O group is in the same side with the NO_2 group,and the N（Me）__2 and the N（Ph）_2are in the different side with the C=O group,compounds have better conduction prop

关 键 词：1 8-萘酰亚胺 前线轨道 吸收光谱 发射光谱 密度泛函 

分 类 号：O641[理学—物理化学]