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靛族染料作为一类重要的还原染料,广泛应用于印染及食品等工业领域,同时在太阳能的贮存和利用、信息记录、液晶材料以及医药等方面也有重要应用前景[1-5]。前人的实验和理论研究表明,靛族染料的颜色源于其分子结构中的给电子-受电子基本发色体(参见图式1),给电子基团X(X=NH,O,S 相似文献
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8-巯基喹啉阴离子的锌配合物及其衍生物的电子光谱性质的含时密度泛函理论研究 总被引:5,自引:0,他引:5
采用从头算(ab initio)和密度泛函理论(DFT B3LYP)方法, 对配合物8-巯基喹啉锌Zn(tq)2及其5种衍生物基态结构进行优化, 用含时密度泛函理论(TD-DFT/B3LYP)及6-31+G(d)基组计算吸收光谱; 同时用ab initio HF 单激发组态相互作用(CIS)法在6-31G(d)基组上优化其最低激发单重态几何结构, 用含时密度泛函理论计算发射光谱. 结果表明, 电子在基态与激发态间的跃迁, 主要是在配体8-巯基喹啉(tq)环内的电荷转移, 电子从含S的苯硫酚环转移至含N的吡啶环上; 吸收光谱和发射光谱的计算值与实验值基本符合. 该类配合物都是优良的电子传输材料, 改变金属离子和取代基均可以调控发光材料的光谱波段. 相似文献
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用密度泛函理论(DFT)以及B3 LYlP泛函在6-311++G**水平上,对苯并咪唑羧酸(L)及其3种碱土金属配合物ML(M=Mg,Ca,Ba)的基态(S0)结构进行优化,用含时密度泛函理论(TD-DFT)在6-311++G**水平下计算其吸收光谱.用单激发组态相互作用(CIS)法在HF/6-31+G*上优化其最低激发单重态(S1)的几何结构,用ID-DFT B3IYP/6-311++G**计算其发射光谱.结果表明,配体L与M(Ⅱ)结合成ML后,随原子序数的增大(Mg相似文献
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8-羟基喹啉铍及其衍生物电子光谱性质的含时密度泛函理论研究 总被引:17,自引:2,他引:17
运用密度泛函理论(DFT)B3LYP方法和abinitioHF单激发组态相互作用(CIS)法分别优化了有机金属配合物8-羟基喹啉铍(BeQ2)及其3种衍生物分子的基态及最低激发单重态几何结构.系统分析了分子结构、前线分子轨道特征和能级分布规律以探索电子跃迁机理.应用含时密度泛函理论(TD-DFT)计算分子的电子光谱,揭示了BeQ2及其衍生物的发光源于配体中π→π*电子跃迁,指出通过配体修饰可以有效地影响配合物前线分子轨道分布,调整发光波段,并有效提高电荷转移量. 相似文献
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CH3和CN取代8-羟基喹啉电子光谱性质的含时密度泛函理论研究 总被引:2,自引:3,他引:2
对8-羟基喹啉QH及其代衍生物MQH和CNQH用密度泛函方法(DFT)在B3LYP/6-31G*水平上进行理论计算,探讨了供电子取代基(-CH3)和吸电子取代基(-CN)对分子电子结构,前线分子轨道能和光谱性质等的影响规律,在此基础上采用含时密度泛涵方法(TD-DFT)计算了电子光谱,计算结果表明,MQH,QH和CNQH的最低激发单重态都是A,激发能分别为3.58,3.72和3.74eV,在高激发态,无论是供电子基团(-CH3)还是拉电子基团(-CN),都导致取代衍生物的电子光谱红移。 相似文献
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苯乙烯基-β-萘噻唑染料电子光谱的含时密度泛函研究 总被引:6,自引:0,他引:6
对苯乙烯基-β-萘噻唑染料系列用量子化学密度泛函方法(DFT)在B3LYP/6-31g水平上进行了几何构型全优化, 探讨了苯环对位上不同的取代基CH3, OCH3, N(CH3)2, 3,4-OCH2O, NO2等对分子电荷转移、前线轨道能量和电子光谱等性质的影响规律, 在此基础上采用含时密度泛函方法(TD-DFT)计算了分子第一激发态的电子跃迁能, 得到最大吸收波长λmax. 计算结果表明, 上述5种取代基的引入, 均导致最大吸收波长红移. 与实验λmax结果相比, 理论计算最大相对偏差为0.0501, 最小相对偏差为0.0085. 相似文献
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BPh-2(mqp)的电子结构和光谱性质的含时密度泛函理论研究 总被引:2,自引:0,他引:2
采用abinitioHF和DFTB3LYP方法,对配合物BPh2(mqp)基态结构进行优化,分析了前线分子轨道特征和能级分布.用abinitioCIS方法优化体系激发态结构.用含时密度泛函理论(TD-DFT)对BPh2(mqp)的电子光谱进行了研究.结果发现,该物质是配体发光配合物,其发光源于mqp配体内π*→π的电子跃迁.这表明在mqp配体上进行修饰,可有效地影响配合物前线分子轨道分布,达到调整发光波段的目的. 相似文献
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MIAO Ti-Fanga ZHANG Jian-Fub LI Shuanga a 《结构化学》2005,24(10):1169-1175
1 INTRODUCTION Pyrazoline compounds have been widely used in industry due to their good photoconductivity and high fluorescence quantum productivity[1]. In recent years, pyrazoline derivatives with high vitrification temperature Tg have been found to act as hole trans- fer materials in the electroluminescence device, which has captured the intensive interest of che- mists[2]. But so far, the electron transfer mechanism of these compounds is still unclear[3~7]. Some resear- ches have attr… 相似文献
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Julien Preat Denis Jacquemin Daniel P. Vercauteren Eric A. Perpète 《Theoretical chemistry accounts》2008,119(5-6):463-468
In this contribution, we set up a SAC-CI methodology to evaluate the n → π* and π → π* vertical transition energies of a series of thiocarbonyl derivatives. We show that Frozen-Core SAC-CI provides accurate
vertical excitations energies. Nevertheless, in order to obtain converged results, the R2S2 unliked integrals have to be taken
into account in L3-SAC-CI calculations. In addition, we present the comparative performances of three computational procedures,
INDO/S, TD-DFT, and SAC-CI, for the calculation of valence excited states energies and it turns out that: (1) no tuning of
the exact exchange (α) included in TD-DFT allows to consistently reproduce the SAC-CI results; (2) SAC-CI and TD-B3LYP both evaluate the n → π*, as well as the π → π* transition energies, with a similar accuracy.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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采用DFT-B3LYP/6-31+G(d)方法,对配聚物[Cd2Cl4(Hbm)2]及其6种衍生物([M2-Cl4(HbmL)2],M=Zn2+,Hg2+;L=-CH3;-NH2;-CN)基态结构进行优化,用TD-DFT/B3LYP/6-31+G(d)方法计算其吸收光谱;同时用HF-CIS/6-31G(d)方法优化其最低激发单重态的几何结构,用含时密度泛函理论计算发射光谱.结果表明:电子在基态与激发态间的跃迁,主要是在卤素配体Cl到金属离子M的电荷转移(LMCL);发射光谱峰的计算最大值与实验值基本符合.改变中心金属离子M和咪唑环上的5位取代基可以精细地调控发光材料的光谱波段. 相似文献
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《中国科学B辑(英文版)》2008,(12)
Making use of a set of quantum chemistry methods, the harmonic potential surfaces of the ground state (S0(1Ag)) and the first (S1(1B3u)) excited state of pyrazine are investigated, and the electronic structures of the two states are characterized. In the present study, the conventional quantum mechanical method, taking account of the Born-Oppenheimer adiabatic approximation, is adopted to simulate the absorp-tion spectrum of S1(1B3u) state of pyrazine. The assignment of main vibronic transitions is made for S1(1B3u) state. It is found that the spectral profile is mainly described by the Franck-Condon progression of totally symmetric mode ν6a. For the five totally symmetric modes, the present calculations show that the frequency differences between the ground and the S1(1B3u) state are small. Therefore the displaced harmonic oscillator approximation along with Franck-Condon transition is used to simulate S1(1B3u) absorption spectra. The distortion effect due to the so-called quadratic coupling is demonstrated to be unimportant for the absorption spectrum, except the coupling mode ν10a. The calculated S1(1B3u) ab-sorption spectrum is in reasonable agreement with the experimental spectra. 相似文献