CAJ | 학술논문

分别采用密度泛函理论(DFT)和单激发组态相互作用(CIS),在6-31G(d,p)基组水平上优化了5个吲哚咔唑分子的基态和激发态结构.在此结构的基础上,用含时密度泛甬理论(TD-DFT)在相同基组水平和极化连续介质模型(PCM)下计算了模型分子的吸收和发射光谱.这几个吲哚咔唑异构体的发射光谱有明显的差别,如异构体5([3,2-b]型)有较大的振子强度,但是相对于其他异构体,其发射能量最小;异构体4([3,2-a]型)的发射能量最大:异构体2([2,3-b]型)的最大振子强度在250-450 nm范围内,与其他几个分子相比为最小.这主要是由分子的激发态几何变化和轨道能级的不同导致的.本文还考察了这类分子的一阶超极化率,结果显示5个分子极化率在同一水平,但静态第一超极化率(β_0)有明显差别,异构体2的β_0值最大.
분별채용밀도범함이론(DFT)화단격발조태상호작용(CIS),재6-31G(d,p)기조수평상우화료5개신타잡서분자적기태화격발태결구.재차결구적기출상,용함시밀도범용이론(TD-DFT)재상동기조수평화겁화련속개질모형(PCM)하계산료모형분자적흡수화발사광보.저궤개신타잡서이구체적발사광보유명현적차별,여이구체5([3,2-b]형)유교대적진자강도,단시상대우기타이구체,기발사능량최소;이구체4([3,2-a]형)적발사능량최대:이구체2([2,3-b]형)적최대진자강도재250-450 nm범위내,여기타궤개분자상비위최소.저주요시유분자적격발태궤하변화화궤도능급적불동도치적.본문환고찰료저류분자적일계초겁화솔,결과현시5개분자겁화솔재동일수평,단정태제일초겁화솔(β_0)유명현차별,이구체2적β_0치최대.
Density functional theory (DFT) and the configuration interaction with single excitations (CIS) method were used to optimize the ground state and excited state structures of five indolocarbazole molecules using the 6-31G (d,p)basis set.Based on their geometric structures,the absorption and emission spectra were calculated using time-dependent DFT(TD-DFT)with the same basis set and employing the polarizable continuum medium model(PCM).There are obvious differenees in the emission spectra of these isomers as isomer 5 has larger oscillator strength in its emission spectrum,but its transition energies are the lowest among the isomers.The emission DeaK value of isomer 4 is the highest and the oscillator strengths of isomer 2 are the weakest from 250 to 450 nm.This is because the structures change from ground state to the excited state and the molecular orbital(MO)energy levels of these molecules are different.We also evaluated the nonlinear optical response (first hyperpolarizability) of this series of molecules.The calculated polarizabilities are similar but the static first hyperpolarizabilities (β_0) are different.The β_0 of isomer 2 is the largest among the compounds investigated.