5,12-二硫杂-7,14-二氮杂-5,7,12,14-四氢并五苯及其相关化合物二阶非线性光学性质的理论研究

在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β_ijk、β_u的程序.研究了不同取代基在5,12-二硫杂-7,14-二氮杂-5,7,12,14-四氢并五苯侧环取代衍生物及相关化合物的结构、光谱和二阶非线性光学性质。结果表明:侧环上取代推、拉电于基团对增大二阶光学非线性都有利;分子共平面,共轭作用强,对增大二阶光学非线性有利.     

含1,3-方酸苯螺旋共轭分子的设计及其电子光谱和非线性光学性质的理论研究

以量子化学半经验方法PM3优化构型为基础,利用INDO/CI方法研究了嵌入1,3-方酸的苯螺旋共轭分子的电子光谱,同时利用INDO/CI-SOS程序计算了它们的二阶非线性光学系数β_ijk和β_μ值,从而探索分子结构与电子光谱及非线性光学性质的关系.理论计算结果表明:在苯螺旋共轭分子中适当地嵌入方酸后,其二阶非线性光学系数增大.与苯螺旋共轭分子和1,3-方酸的比较表明,方酸环处于左端的体系有很好的二阶非线性光学性质,可能成为较好的光学材料.     

螺旋共轭分子2,2′-螺二茚-1,1′, 3,3′-四酮及其衍生物的二阶非线性光学性质与分子结构关系的研究

采用AM1和ZINDO系列方法研究了螺旋共轭分子2,2′-螺二茚-1,1′, 3,3′-四酮及其含氮衍生物的几何构型和各分子的稳定构型, 并以稳定构型为基础, 计算了这些分子的电子光谱、二阶非线性光学系数βμ, β0及电荷转移, 考察了取代基变化对βμ的影响. 计算结果表明, 所设计分子兼具较大的二阶非线性光学系数和较高的透过率, 有希望成为一类新型的二阶非线性光学材料.     

(二噻吩[3,2-b:3',2'-d]环戊烷-4-亚基)C60中的分子轨道相互作用及其电子光谱和二阶非线性光学性质

在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β的程序.研究了(二噻吩[3,2-b:3',2'-d]环戊烷-4-亚基)C₆₀中的分子轨道相互作用,计算了该分子的电子光谱和二阶非线性光学系数卢,前者与实验结果吻合较好,后者属于理论预测性质.     

(4,5-二氮杂-9-亚芴基)碳60中的分子轨道相互作用及其电子光谱和二阶非线性光学性质

在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β的程序.研究了(4,5-二氮杂-9-亚芴基)碳60中的分子轨道相互作用,计算了该分子的电子光谱和二阶非线性光学系数,前者与实验结果较好地吻合,后者属于理论预测性质.     

2-苯基苯并咪唑衍生物非线性光学性质的从头算研究

采用HF／6-31G^*方法优化分子构型，在此基础上用CPHF方法系统地研究了多种基团取代的2-苯基苯并咪唑衍生物的二阶非线性光学系数βvec，并对βvdc的影响因素进行了探讨，为进一步设计综合性能优良的有机非线性光学材料提供理论指导．     

2,4-二吡啶基方酸衍生物非线性光学性质的从头算研究

采用HF/4-31G方法优化分子几何构型,在此基础上用CPHF研究了系列2,4-二吡啶基方酸衍生物的二阶非线性光学系数βvec,并对影响βvec的因素进行了探讨.结果表明:此类化合物均有很大的βvec,它们的非线性光学性质与其分子结构有着密切的关系.     

对硝基二苯乙炔系列衍生物的二阶非线性光学性质的理论研究

在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β_ijk和β_μ的程序,研究了对硝基二苯乙炔系列衍生物的结构和非线性光学性质,考察了分子共轭链长和给电子基团对β_μ的影响.结果表明,对硝基二苯乙炔系列衍生物上连有推电子基团有利于增大二阶光学非线性,扩大共轭范围也有利于增大二阶光学非线性,但对透明性则影响不大.     

系列新推拉型多环共轭分子二阶非线性光学性质的理论研究

在AM1和ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β_ijk和β_μ的程序,研究了一系列新推拉型多环共轭分子的结构、光谱和二阶非线性光学系数β(-2ω,ω,ω)和β(0,0,0).考察了分子共轭链长、分子骨架和给电子取代基对β_μ的影响,并设计了具有最大β_μ的新型非线性光学材料分子.     

取代吡啶系列分子的光谱和二阶非线性光学性质的理论研究

采用AM1方法优化分子构型,用ZINDO方法研究了氨基、硝基取代的吡啶系列分子的电子光谱,并在此基础上用自编程序计算了这些分子的二阶非线性光学系数,对取代吡啶系列分子的二阶非线性光学系数的影响因素进行了探讨,并在微观上给予了解释。     

Unlocking the Remarkable Influence of Intramolecular Group Rotation for Third-order Nonlinear Optical Properties

This work exposes for the first time the remarkable influence of intramolecular group rotation on third-order nonlinear optical (NLO) performance. In order to prove the role of group rotation, we designed and synthesized two photo-response compounds tetramethyl 5,5′-(((diazene-1,2-diylbis(4,1-phenylene))bis(oxy))bis(methylene))diisophthalate (1) and 5,5′-(((diazene-1,2-diylbis(4,1-phenylene))bis(oxy))bis(methylene))diisophthalic acid (2) and investigated their NLO performance under different substituent (benzyloxy group) rotation states. 1 and 2 have dynamic benzyloxy group rotation in dilute solution and shows reverse saturated absorption (RSA). When the benzyloxy group rotation of 1 and 2 was restricted by PMMA, their NLO performance not only converted into saturated absorption (SA) and NLO refraction behaviours, but also hardly changed after isomerization. Interestingly, we also restricted the benzyloxy group rotation in solution to a certain extent through photo-induced trans→cis isomerization, and found that the NLO performances of cis isomers of 1 and 2 exhibit SA and positive refraction and are similar to those of 1 -PMMA and 2 -PMMA. This work provides a new exploratory method for studying the influencing factors of third-order NLO performance.     

Development of calculation and analysis methods for the dynamic first hyperpolarizability based on the ab initio molecular orbital-quantum master equation method

We develop novel calculation and analysis methods for the dynamic first hyperpolarizabilities β [the second-order nonlinear optical (NLO) properties at the molecular level] in the second-harmonic generation based on the quantum master equation method combined with the ab initio molecular orbital (MO) configuration interaction method. As examples, we have evaluated off-resonant dynamic β values of donor (NH(2))- and/or acceptor (NO(2))-substituted benzenes using these methods, which are shown to reproduce those by the conventional summation-over-states method well. The spatial contributions of electrons to the dynamic β of these systems are also analyzed using the dynamic β density and its partition into the MO contributions. The present results demonstrate the advantage of these methods in unraveling the mechanism of dynamic NLO properties and in building the structure-dynamic NLO property relationships of real molecules.     

联吖叮氮氧自由基体系及其衍生物NLO性质的密度泛函理论研究

以实验合成的联吖叮氮氧自由基分子为母体, 设计了7个自由基分子. 采用密度泛函理论(DFT) UB3LYP/6-31g(d,p)方法对这些自由基分子不同自旋态的稳定性和非线性光学(NLO)系数进行计算. 结果表明, 联吖叮氮氧自由基分子及其衍生物三重态为稳定基态, 符合自旋极化规则. 引入给吸电子取代基使自由基体系的极化率αs与二阶超极化率γs值有所增大, 且基团的给吸电子能力越强, αs和γs值增加越明显; 对于一阶超极化率βtot, 自由基体系处于单重态时, 取代基的影响较大. 所有自由基分子三重态的NLO系数都小于单重态, 表明可以通过控制体系的自旋多重度来调节体系的NLO性质.     

Tailoring the donor moieties in TPA-based organic dyes for efficient photovoltaic,optical and nonlinear optical response properties

The current study reports tailoring the electronic donor structures of organic dyes to modify their optical and nonlinear optical (NLO) response properties. Five (5) tri-phenyl amine (TPA) based Donor-π-Acceptor (D-π-A) organic dyes with the codes ICAA1 , ICAA2 , ICAA3 , ICAA4 , and ICAA5 were designed and investigated for their optical and NLO properties using quantum chemical methods. Optical and NLO properties of these dyes were studied by CAM-B3LYP method and 6-311G* basis set. The focus has been on the impact of adding secondary donors and shifting their substitutions at ortho (o), meta (m) and para (p) positions. Among all designed compounds, ICAA4 showed the highest amplitude of average third-order NLO polarizability <γ>, which is calculated to be 1316 × 10⁻³⁶ esu. Time-dependent Density Functional Theory (TD-DFT) method was used to determine how a change in the position of the donor affected the excitation energy (E_g) and NLO response properties. The findings showed that changing the position of the secondary donor results in a red shift among absorption spectra as well as the increase in their NLO responses. Complete process of intramolecular charge transfer (ICT) has been investigated in terms of different optical parameters such as frontier molecular orbitals (FMOs), molecular electrostatic potentials (MEPs), transition density matrix (TDMs), density of states (DOS), electron density difference (EDD), and natural bond orbital (NBO) analysis. Our calculations for study of ICT process indicate that p-position of methoxy group performs better among all other positions and even it has better NLO response properties than the compound with three collective methoxy groups. The calculated V_oc values of all designed molecules range from 1.09 to 1.30, all of them are positive while their ΔG_inject is found to be in the range of −0.87 to −1.79 eV indicating their decent potential for photovoltaic applications. The studied optical, NLO and photovoltaic parameters illustrated that ICAA1 to ICAA5 are appropriate molecules not only for NLO applications but also for efficient photovoltaic purposes.     

两种含偶氮苯共轭桥新型生色团分子的合成及性能

通过重氮化偶合反应和羟醛缩合反应合成了以偶氮苯为共轭桥、以2,2,3-三甲基-4-氰基-5-二氰基亚甲基-2,5-二氢呋喃为电子受体, 而给体分别为二甲氨基和二乙氨基的两种有机非线性光学生色团分子MFNC和EFNC. 利用IR、1H NMR和元素分析对分子的结构进行了表征. TGA和DSC测试发现, MFNC的热稳定性略好于EFNC, 其热分解温度最高达266 ℃. 通过测定两种材料在氯仿、丙酮和DMSO中的紫外-可见光谱, 用溶致变色法计算得到两种材料在激光波长为1064 nm处的二阶非线性品质系数μgβ, 对比发现EFNC的μgβ值高于MFNC, 其值达59706×10-48 esu(1 esu=3.34×10-10C).     

Second-order Nonlinear Optical Properties of a Series of Benzothiazole Derivatives

The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method.These chromophores are formed by a donor- π- bridge-acceptor system,based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl-functional amino group as the donor.For the purpose of comparison,we also designed molecules in which nitrobenzene is an acceptor,The calculation results indicate that benzothiazole derivatives exhibit larger second-odrder polarizabilities than nitrobenzene derivatives.In order to clarify the origin of the NLO response of these chromophores,their electron properties were investigated as well.The benzothiazole derivatives are good candidates for application in electro-optical device due to their high optical nonlinearities,good thermal and photonic stability.     

An effective method for accurate prediction of the first hyperpolarizability of alkalides

The proper theoretical calculation method for nonlinear optical (NLO) properties is a key factor to design the excellent NLO materials. Yet it is a difficult task to obatin the accurate NLO property of large scale molecule. In present work, an effective intelligent computing method, as called extreme learning machine-neural network (ELM-NN), is proposed to predict accurately the first hyperpolarizability (β(0)) of alkalides from low-accuracy first hyperpolarizability. Compared with neural network (NN) and genetic algorithm neural network (GANN), the root-mean-square deviations of the predicted values obtained by ELM-NN, GANN, and NN with their MP2 counterpart are 0.02, 0.08, and 0.17 a.u., respectively. It suggests that the predicted values obtained by ELM-NN are more accurate than those calculated by NN and GANN methods. Another excellent point of ELM-NN is the ability to obtain the high accuracy level calculated values with less computing cost. Experimental results show that the computing time of MP2 is 2.4-4 times of the computing time of ELM-NN. Thus, the proposed method is a potentially powerful tool in computational chemistry, and it may predict β(0) of the large scale molecules, which is difficult to obtain by high-accuracy theoretical method due to dramatic increasing computational cost.     

Na2BaMQ4 (M=Ge,Sn; Q=S,Se): Infrared Nonlinear Optical Materials with Excellent Performances and that Undergo Structural Transformations

Infrared nonlinear optical (IR NLO) materials with excellent performances are particularly important in laser technology. However, to design and synthesize an efficient IR NLO material with a balance between the optical band gap and the NLO coefficient is still a huge challenge. With this in mind, four new IR NLO materials Na₂BaSnS₄, Na₂BaSnSe₄, Na₂BaGeS₄, and Na₂BaGeSe₄ were successfully designed and synthesized. The compounds exhibit excellent properties with a suitable balance of band gap and NLO coefficient measured for Na₂BaSnS₄ (3.27 eV and about 17×KDP, that is, about 17 times that of KH₂PO₄ (KDP)) and Na₂BaGeS₄ (3.7 eV and about 10×KDP), demonstrating that the systems satisfy the key requirements as promising IR NLO candidates. Remarkably, the new compounds also undergo a novel structural transformation from tetragonal to trigonal systems, the first time that this has been reported for quaternary metal chalcogenides.     

高热稳定性和可逆交联性质的含新型偶氮发色团电光聚合物的研究(英文)

制备了两种新型的分别含有以三苯胺为电子给体的偶氮类发色团作为特征活性官能团和3-呋喃甲酸及受保护的马来酰亚胺的可交联型聚合物体系.通过研究表明利用该制备方法,发色团在聚合物中的含量得到了极大的提高,分别达到32 .1 %( NLO1-P1)和44 .4 %( NLO1-P2) .该聚合物体系以"Diels-Alder"[4 +2]环加成反应作为其交联特征,具有高温非交联、低温交联的特点,其过程与以往的热交联型聚合物相反,可解决传统电光交联聚合物中存在的热交联对极化效率影响的问题并用热失重分析法(TGA)和差示扫描量热法(DSC)分析了这一过程.此外DA交联型聚合物,不需要引入额外的助交联剂,克服了传统热交联聚合物分离难的问题,最大程度的保证了材料的纯度.     

Influence of acceptor tethering on the performance of nonlinear optical properties for pyrene-based materials with A-π-D-π-D architecture

In this study, we designed a series of pyrene-based donor-π-donor-π-acceptor compounds (HPTC1-HPTC7) by structural tailoring the reference compound (HPTC) using acceptor units. Nonlinear optical (NLO) properties, frontier molecular orbitals (FMOs), natural bonding orbital (NBO), transition density matric (TDM) analysis, and absorption spectra of reference and proposed derivatives were calculated at M06/6-31G(d,p) functional. All the designed compounds have smaller energy bandgaps than the HPTC compound. Moreover, the designed compounds exhibited larger global softness values than the reference. The absorption maxima of HPTC2, HPTC3, and HPTC7 are blue shifted with respect to HPTC. NBO analysis revealed that prolonged hyper conjugative associations and strong interactions between the donor (π) and acceptor (π*) moieties play a crucial part in their stabilization. The FMO and NBO findings supported the NLO responses of entitled compounds, and consequently, the linear and nonlinear properties of designed derivatives elevate compared to the reference molecule. Promisingly, the NLO response for HPTC7 comprises of highest values of <α>, β_total and < γ > as 1.92 × 10^?22 esu, 1.95 × 10^?27 esu, and 4.69 × 10⁷ (a.u). This NLO behavior shows push–pull NLO chromophores for HPTC7 predicting its role in pursuing NLO materials for optoelectronic applications.