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1.
吴玉辉  周欣  张红星 《化学学报》2009,67(3):197-202
采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(II)二亚胺配合物[Os(L)2(CN)2(phen)] [phen=1,10-邻二氮杂菲; L=Ph3 (1), 二甲基亚砜(DMSO) (2)]及[Os(PH3)2(phen)Br2] (3)的基态和激发态几何构型. 通过TD-DFT方法结合PCM溶剂化模型计算了配合物1~3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质. 通过理论化学计算, 揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因. 并进一步解释了配合物3易于在Os—Br键处断裂而发生反应的量子化学机理. 对配合物在不同溶剂中的磷光发射性质的计算表明, 溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应.  相似文献   

2.
采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(Ⅱ)二亚胺配合物[Os(L)2(CN)2(phen)][phen=1,10-邻二氮杂菲;L=PH3(1),二甲基亚砜(DMSO)(2)]及[Os(PH3)2(phen)Br2](3)的基态和激发态几何构型.通过TD-DFT方法结合PCM溶剂化模型计算了配合物1~3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质.通过理论化学计算,揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因.并进一步解释了配合物3易于在Os-Br键处断裂而发生反应的量子化学机理.对配合物在不同溶剂中的磷光发射性质的计算表明,溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应.  相似文献   

3.
用量子化学密度泛函理论 B3 LYP方法 ,在 6-3 1 G( d)水平上对环硼氮烷和苯基对称取代方酸进行几何构型优化 .以此为基础 ,利用 TD-DFT方法得到方酸衍生物的 UV-Vis吸收光谱 .进一步引入外电场 ,用有限场 ( FF/ DFT-B3 LYP)方法探讨了各体系的三阶非线性光学性质 ( NLO) .计算结果显示 ,对称环硼氮烷取代的方酸衍生物性质不同于苯环取代 ,取代位置对电荷分布、分子轨道特征和非线性光学性质的影响很大 .氮原子与方酸相连时对提高方酸体系的三阶非线性光学性质十分有效 ,其 NLO系数可达 2 .3 80 8×1 0 -2 4C·m.  相似文献   

4.
郭佳  赵清岚 《化学研究》2010,21(6):82-84,90
采用B3LYP/6-31G(d,p)方法优化得到了并三噻吩(DTT)及其三种衍生物苯基并三噻吩(PDTT)、萘基并三噻吩(TDTT)和噻吩基并三噻吩(NDTT)基态(S0)的稳定几何构型,并通过频率分析加以验证.在TD-B3LYP/cc-pVTZ水平下,计算了它们的电子吸收光谱,计算值与实验值符合得很好.计算结果表明:它们的吸收波长顺序为λNDTTλTDTTλPDTTλDTT.采用TD-B3LYP/6-31G(d,p)方法,优化得到了TDTT和NDTT第一激发态(S1)的几何结构,并在TD-B3LYP/cc-pVTZ水平下计算了它们的发射光谱.  相似文献   

5.
采用密度泛函理论(DFT)B3LYP方法,对含二茂铁双Schiff碱配体及其Ni(Ⅱ)配合物的几何构型进行优化.在得到稳定构型的基础上,采用含时密度泛函理论(TD-DFT)的B3LYP方法计算了配合物的电子光谱,并结合有限场(FF)方法研究了配体和配合物的极化率和二阶非线性光学(NLO)性质.结果表明,配体中引入Ni(...  相似文献   

6.
线性簇合物SC2nS2-(n =1~12)电子吸收光谱   总被引:2,自引:0,他引:2  
应用密度泛函理论,在B3LYP/6-31G*水平上优化了线性簇合物SC2nS2-(n =1~12)的基态平衡几何结构,并计算了它们的谐振动频率.在基态平衡构型下,通过TD-B3LYP/cc-pvTZ和TD-B3LYP/cc-pvDZ计算,确定了簇合物SC2nS2-(n =1~10) 电子跃迁的垂直激发能和对应的振子强度.基于计算结果,导出了电子跃迁吸收波长与体系大小n的解析关系式,以及SC2nS2-体系第一电离能与体系大小n的解析表达式,并讨论了不同端位原子对碳链体系激发态性质的影响.  相似文献   

7.
合成了PCPDTBT,通过NMR,GPC等方法对聚合物进行了表征.研究了聚合物的热学与电化学性质.采用溶液法将电子给体PCPDTBT与两种电子受体1-(3-甲氧基羰基)丙基-1-苯基[6,6]C61(PCBM)和ZnO纳米粒子分别进行了复合,通过研究复合前后的荧光变化,确认了给体-受体两相界面间发生了由分子能级差引发的光致电荷转移.这些研究结果为探索性能更佳的有机太阳能电池材料体系提供了重要的参考依据.  相似文献   

8.
用电子转移的半经典模型在量子化学B3LYP/6-31G(d)水平(对单体)和B3LYP/STO-3G水平(对二聚物)对环聚炔苯和环聚炔吡啶组成的盘状液晶体系的电荷转移性质进行了研究. 盘状液晶体系的电荷转移速率主要依赖于重组能和电荷转移矩阵元, 重组能越小, 电荷转移矩阵元越大, 则电荷转移速率常数越大. 计算结果表明, 这些大环化合物比目前广泛研究和应用的苯并菲衍生物组成的液晶有较小的重组能, 所以有更好的电荷转移性质. 计算结果对有效地设计和合成高效的光导材料和载流子输送材料是有帮助的.  相似文献   

9.
应用密度泛函理论,在B3LYP/6-31G水平上优化了线性簇合物SC2nS2-(n=1~12)的基态平衡几何结构,并计算了它们的谐振动频率.在基态平衡构型下,通过TD-B3LYP/cc-pvTZ和TD-B3LYP/cc-pvDZ计算,确定了簇合物SC2nS2-(n=1~10)X1Σ g→11Σ u电子跃迁的垂直激发能和对应的振子强度.基于计算结果,导出了X1Σ g→11Σ u电子跃迁吸收波长与体系大小n的解析关系式,以及SC2nS2-体系第一电离能与体系大小n的解析表达式,并讨论了不同端位原子对碳链体系激发态性质的影响.  相似文献   

10.
采用密度泛函理论DFT(B3LYP/6-3G)对氧取代后叶绿素的几何构型进行优化,并用不同的量子化学方法如ZINDO-CIS,TD-DFT和SAC-CI计算激发态能量,考察叶绿索的侧链和单线态根数目对激发态能量的影响,并计算Q,态跃迁偶极矩与y轴的夹角.结果表明,CAM-B3LYP泛函形式是计算叶绿素a前4个激发态特征...  相似文献   

11.
[2.2]Paracyclophane-based through-space conjugated oligomers and polymers were prepared, in which poly(p-arylene-ethynylene) (PAE) units were partially π-stacked and layered, and their properties in the ground state and excited state were investigated in detail. Electronic interactions among PAE units were effective through at least ten units in the ground state. Photoexcited energy transfer occurred from the stacked PAE units to the end-capping PAE moieties. The electrical conductivity of the polymers was estimated using the flash-photolysis time-resolved microwave conductivity (FP-TRMC) method and investigated together with time-dependent density functional theory (TD-DFT) calculations, showing that intramolecular charge carrier mobility through the stacked PAE units was a few tens of percentage larger than through the twisted PAE units.  相似文献   

12.
彭亚晶  付星  蒋艳雪 《化学通报》2015,78(10):923-927
采用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)研究了气相水杨酸(SA)分子的激发态氢键动力学过程。通过对水杨酸分子基态和激发态结构的优化,以及对其稳态吸收和发射光谱特性、前线分子轨道、红外振动光谱和势能曲线的计算分析,阐明水杨酸分子内质子转移可在激发态下自发地发生,导致其激发态可存在烯醇式和酮式两种异构体结构,并揭示了这种质子转移源于分子内电荷转移的激发态氢键的加强机制。  相似文献   

13.
采用量子化学方法研究了2种新型有机染料分子P1和P4,几何优化和基态性质计算采用B3LYP密度泛函,基组为6-311G(d).由于P1和P4分子中分别存在2个对称的吸电子基团,所以2个染料分子的电子结构存在明显的特点:2个紧邻简并最低空轨道(LowestUnoccupied Molecular Orbital,LUMO)轨道.P1和P4最高占据轨道(Highest Occupied Mo-lecular Orbital,HOMO)到LUMO轨道的跃迁能级差分别为2.79和3.26eV.同时,采用含时密度泛函方法(Time-Dependent Density Functional Theory,TDDFT)研究了2个染料分子的激发态性质.通过电荷差异密度理论方法(Charge Different Density,CDD)直观的展示了分子内电荷转移的现象.对于P1,电荷转移的方向是从苯甲酸基团到2个二氰乙烯基噻吩苯基团;对于P4,电荷是由2个二氰乙烯基联苯基团基团向苯甲酸基转移.  相似文献   

14.
This work reported an investigation on the excited state and electronic transfer excitation of cuprous (I) bis-phenanthrouline complex by density functional theory. The intramolecular charge transfer from central metal to ligand (MLCT) during the excitation was observed. The transfer direction and degree were discussed on the basis of analyzing the Mulliken charge. The structural distortion caused by the charge transfer in the excited state was confirmed. The excited state was found having the characters similar with Cu(II) complex both in electronic and geometrical properties. The large structural distortion found between ground state and excited state could lead to a decrease in the lifetime of excited state as well as a non-radiative decay. The excitation energies and oscillator strengths of cuprous (I) bis-phenanthrouline were derived using time-dependent density functional method. The values of excitation energies are good agreement with the results of the experimental measuring.  相似文献   

15.
用含时的密度泛函(TD—DFT)方法研究了低带隙的中性和带电的交替共聚芴Green 1),该化合物是由烷染取代芴和(1,2,5-噻吩基-3,4-硫重氮基)喹喔啉噻吩(T—TDQ—T)单元交替重复组成,对他们的激发态特性用二维(2D)和三维(3D)实空间分析方法做了进一步分析.对于中性的Green 1,分别得到其带隙、键能、激子结合能和核驰豫能.用3D跃迁密度方法对中性和带电的Green 1的跃迁偶极矩进行比较可显示出跃迁偶极矩的取向和强度;用3D电荷差异密度方法显示出激发后的中性和带电的Green 1电荷重新分布和比较,用2D实空间分析方法(跃迁密度矩阵)来研究中性和带电的Green 1处于激发态时的电子空穴相干性.中性Green 1的激发态特性分别用TD—DFT和ZINDO两种方法进行了计算,比较得出电子-电子相互作用(在TD—DFT中)对激发态性质的重要影响.  相似文献   

16.
The structural and electronic properties of a photochromic molecule dictate their potential photochemical activity. To gain insight into these influences, the ground‐state structure and excited state properties of six indolylgulgides were calculated using several time dependent‐density functional theory (DFT) (TD‐DFT)//DFT methods, second‐order M?ller–Plesset (MP2), and CIS(D). These methods simulated the charge‐transfer properties and the conformation of the ground‐state structure for each molecule. Generally, TD‐DFT accurately simulated the expected charge‐transfer state. The degree of spatial overlap of the occupied and virtual molecular orbitals involved in the S1 transition of indolylfulgides quantitatively assessed their charge‐transfer character and was qualitatively useful in assessing their photochromic activity. The M06, M06‐2X, and M11 structures were quite similar to those calculated by MP2. Structural differences, similarities, and functional trends are compared and discussed. © 2013 Wiley Periodicals, Inc.  相似文献   

17.
[2.2]Paracyclophane‐based through‐space conjugated oligomers and polymers were prepared, in which poly(p‐arylene–ethynylene) (PAE) units were partially π‐stacked and layered, and their properties in the ground state and excited state were investigated in detail. Electronic interactions among PAE units were effective through at least ten units in the ground state. Photoexcited energy transfer occurred from the stacked PAE units to the end‐capping PAE moieties. The electrical conductivity of the polymers was estimated using the flash‐photolysis time‐resolved microwave conductivity (FP‐TRMC) method and investigated together with time‐dependent density functional theory (TD‐DFT) calculations, showing that intramolecular charge carrier mobility through the stacked PAE units was a few tens of percentage larger than through the twisted PAE units.  相似文献   

18.
Three new D-π-A type compounds, each containing one benzothiazole ring as an electron acceptor and one N-ethylcarbazole group as electron donor, were synthesized and characterized by elemental analysis, NMR, MS and thermogravimetric analysis. The absorption and emission spectra of three compounds were experimentally determined in several solvents and were simultaneously computed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The calculated reorganization energy for hole and electron indicates that three compounds are in favor of hole transport than electron transport. The calculated absorption and emission wavelengths are well coincident with the measured data. The calculated lowest-lying absorption spectra can be mainly attributed to intramolecular charge transfer (ICT). And the calculated fluorescence spectra can be mainly described as originating from an excited state with intramolecular charge transfer (ICT) character. The results show that three compounds exhibited excellent thermal stability and high fluorescence quantum yields, indicating their potential applications as excellent optoelectronic material in optical field.  相似文献   

19.
The geometries, spectroscopic and electronic structures properties of a series of heteroleptic phosphorescent Ir(III) complexes including N981, N982, N983, N984 have been characterized by density functional theory calculations. The excited‐state properties of the Ir(III) complexes have been characterized by CIS method. The ground‐ and excited‐state geometries were optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ levels, respectively. By using the time‐dependent density functional theory method, the absorption and phosphorescence spectra were calculated based on the optimized ground‐ and excited‐state geometries, respectively. The results show that the absorption and emission data agree well with the corresponding experimental results. The calculated results also revealed that the nature of the substituent at the 4‐position of the pyridyl moiety can influence the distributions of HOMO and LUMO and their energies. In addition, the charge transport quality has been estimated approximately by the calculated reorganization energy (λ). Our result also indicates that the positions of the substitute groups not only change the transition characters but also affect the charge transfer rate and balance, and complex N982 is a very good charge transfer material for green OLEDs. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009  相似文献   

20.
石墨烯条带的电子结构与性质:电场及长度效应   总被引:1,自引:0,他引:1  
在密度泛函理论(DFT)和含时密度泛函理论(TDDFT)的基础上对宽度上含有8个zigzag链的石墨烯条带(8-ZGNR)的基态和激发态的性质进行了理论研究,着重考察了条带长度及电场的影响.B3LYP杂化泛函的计算结果显示:在基态上,8-ZGNR的最低能量态并不具有磁性,随着长度的增加,才会显示出反铁磁的性质.静电场的加入使8-ZGNR显示出反铁磁性和半金属性.在激发态上,诱导电子会随着外激光脉冲的变化而发生移动和变化,但是相比而言,α自旋电子更容易被激发而产生较明显的诱导电子密度,而β自旋电子则更容易脱离外激光场的控制而产生非绝热现象.  相似文献   

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