同系物分子结构与物理化学性能间的定量关系Ⅳ.共轭多炔链物电子光谱中的同系线性规律

本文讨论了23个共轭多炔链物系列中电子吸收光谱的同系线性规律。在具有非共轭端基或单共轭端基的炔链物中(L-1至L-8),同系线性规律与近似线性叠合规律[式(2)与式(3)]的关联情况都很良好,并且与多烯链物完全一致。但是在具有两个共轭端基的炔链物中(L-9至L-23),需将同系序数加以校正(校正的同系序数N'=(1/2)N+4),才能保持良好的同系线性关系。在这一类中,β值的递变情况与烯链物不同,而与骈苯链物一致。     

查耳酮类化合物的代基效应

查耳酮类化合物是一类合流型三岔共轭化合物。对于这类三岔共轭体系中的结构效应,前文中已在同系线性规律的基础上进行了比较系统的研究。但对于作为代基一岔的结构效应研究的不多,对于不同电性的取代基引入苯基后,所导致的同系直线斜率的变化是否与取代基的极性存在一定关系,尚待进行研究。本文合成了5个苯多烯基4＇-取代苯基酮系共20个化合物和一个相应的线型体系——苯多烯醛。研究了     

呋喃多烯酸酯类三岔共轭体系结构和性能之间的定量关系Ⅱ——核磁共振和红外光谱

本文测定了 FN-n,FE-n,FNE-n 和 FM-n 四个系列的核磁共振谱及红外光谱.核磁共振谱中,α氢的吸收峰在最高场,而β氢的吸收峰在最低场.随着共轭链的增长,α,β氢的吸收峰都向高扬移动.它们的化学位移与结构之间的关系近似地遵循同系线性规律.和核磁共振相似,红外光谱的 c=c,c=o 伸缩振动频率和结构之间的关系也近似地遵循同系线性规律.     

有机同系物的指数型同系线性规律（Ⅱ）──共轭多烯链状化合物电子光谱的验证

用共轭多烯链状化合物电子光谱的数据,对指数型同系线性规律进行验证。结果表明指数型同系线性规律具有广泛适用性和较高精确度。在所研究的７１个系列１６９组吸收峰数据中,相关系数属于“优”和“良”的组数总和占总数的９９％以上。     

冠醚查耳酮类化合物的合成及其性能的研究

本文合成了四个4′-苯多烯酰基苯并15-冠-5和一个4′-苯酰基苯并15-冠一5等五个三岔共轭化合物。测定了它们的电子吸收光谱,红外光谱。并用同系因子(1/2)~(2/N)考查了这类三岔共轭体系的同系递变关系。用相似三角形法计算的较短分岔基团苯并15-冠-5的代基当量值△N_5为0.854。这表明苯并15-冠-5不权起代基作用而且它与羰基之间还有一定的共轭作用,约相当于一个双键。此外,还合成了四个3′,4′-二甲氧基苯多烯酮类化合物,将它们的电子光谱与冠醚查耳酮类化合物的进行了比较。     

有机同系物的指数型同系线性规律（Ⅰ）—光电子能谱数据的验证

本文提出一种未报道过的指数型同系线性规律，其表示式为：Ｐ＝ａ＋ｂｅｘｐ｛（ｋ＋１）／（２Ｎ＋３）｝用有机共轭同系物和非共轭同系物的光电子能谱数据对该线性规律进行了验证。     

电子等排体的噻吩多烯与苯多烯同系递变的比较Ⅱ

为了比较噻吩多烯和苯多烯三岔共轭体系的性能,合成了三个系列带两个拉电子基团的噻吩多烯三岔化合物(TDn,TEn,TFn),测定了它们在环已烷和乙醇中的电子吸收光谱。实验表明,带两个拉电子基团的噻吩多烯三岔共轭化合物的电子吸收光谱频率也都遵守同系线性规律,相关系数Υ>0.99。与相应的苯多烯化合物的电子光谱相比,吸收峰普遍地红移一个插烯双键所引起的红移数值。相应的同系直线相距很近。△λ_(th)/△λ_E值为0.83-1.10。第一个拉电子基团的引入,化合物的电子吸收峰红移30nm左右,但当第二个拉电子基团引入时,电子吸收峰仅红移3—17nm,其作用只相当于一个取代基。     

三岔共轭体系中的结构效应(Ⅵ)——氮杂查耳酮类化合物红外光谱中的同系线性规律

本文合成并研究了2P0nB、4P0nB、2Q0nB等11个三岔共轭化合物的红外光谱。实验表明这些化合物的基因特征吸收波数近似地遵守同系线性规律,相关系数r为0.982-1.000,与相应线性体系的同系直线比较,它们的斜率较小。这表明一个分岔的引入导致基因特征吸收波长红移,并表明在三岔体系中是分子整体性占优势而分岔基团的特性是受到分子整体性制约的。     

芳杂环共轭聚合物紫外吸收光谱的递变规律

对芳杂环共轭聚合物的同系线性规律进行了探讨,提出了一种芳杂环共轭聚合物紫外吸收光谱递变规律,其表达式为：P=a b(1／n)。用芳杂环聚合物共轭体系的紫外吸收光谱实验数据对该线性规律进行了验证。结果表明,该表达式线性相关系数较徐光宪提出的线性规律公式要好,且预测芳杂环聚合物紫外吸收光谱比较准确。     

脂肪多烯酸β-萘酯端外基团的结构效应

根据同系线性规律,在共轭体系中分子整体性往往是占优势的结构因素,而基因特殊性或相对独立性则是从属的因素。但是,在一个共轭化合物中,当端外基因很大,而同系基干较小时,则端外基团也可以表现优势。这样,在复杂系列化合物的同系直线上就会出现一个转折点。根据以上设想,我们合成了脂肪多     

Use of partial molar volume for determining conformations of macromolecules in a solution

A formula was derived for determining the partial molar volume (PMO) of solute at various concentrations and on this basis a method was developed for determining the PMO at infinite dilution. The partial molar volumes of the homologous series of poly(ethylene glycol) with molecular masses 400, 1000, 1500, 2000, 4000, 20000 in aqueous solutions at infinite dilution were determined. Analysis of the calculated and experimental PMO showed that poly(ethylene glycol) molecules exist in dilute solutions in the conformations of elongated helices. In addition, the high-molecular polyethylene glycol molecules include the areas of statistical chaos, which leads to sites unavailable for the solvent molecules. Based on literature data were revealed the values of PMO for highly concentrated solutions of poly(ethylene glycol) PEG 400, PEG 4000, and PEG 6000. Effect of concentration on the structure of PEG solutions was demonstrated. We found that in the temperature range 25–40°C the conformational transitions were not observed.     

用DVR方法研究Ar-HF和Ar-DF的振转光谱

本文用离散变量表示(DVR)方法研究了Ar-HF和Ar-DF体系的振转光谱。对这两个体系的已观测到的振转能级, 用DVR方法得到的计算值与实验结果十分吻合, 误差一般小于0.1cm^-^1, 最大偏差为0.24cm^-^1对Ar-HF的(1113)态。该研究结果与Hutson等用耦合孔道法得到的计算结果基本一致, 但对(3210)振动能级和对(3002)-(3110)态的能级分裂值, 本文计算结果更接近观测值。     

呋喃多烯酸酯类三岔共轭体系结构和性能之间的定量关系——(Ⅰ)紫外光谱

本文合成及制备了下述六个系列的化合物并测定了它们的紫外光谱、质谱。结果表明: α-C_4H_3O-(CH=CH)nCHO (FA-n) n=2,3,4,5。 α-C_4H_3O-(CH=CH)nCN FN-n) n=1,2,3~*,4~*,5~*。 α-C_4H_3O-(CH=CH)nCO_2Et (FE-n) n=1,2,3~*,5~*。 α-C_4H_3O-(CH=CH)nCH=C(CN)CO_2H (FNA-n)n=0,1,3~*,4~*。 α-C_4H_3O-(CH=CH)nCH=C(CN)CO_2Et (FNE-n)n=0,1,3~*,4~*, α-C_4H_3O-(CH=CH)nCH=C(CO_2Et)_2·(FM-n) n=0,1,3~*,4~*,5~*。 (*:表示文献中未知的化合物) 在环己烷、乙醇,甲醇和四氯化碳溶剂中各组电子吸收峰的波数与同系因子相联系时,都各有一条而且只有一条良好的直线。同系线性规律的专一性表明了,在呋喃多烯三岔系列中,呋喃环的端基当量仍然是2。并不因为在烯链的另一端具有两个强吸电子的共轭分岔基团的存在而增大呋喃环的端基当量。在FM-n系列中,利用经验公式算得的Sj′以及利用相似三角形式算得的sj的平均值都在0.4左右。这就定量地表明了,在末端二个羧酸酯基中,只可能有一个是端基,而另一个是代基。λ′计-λ实的最大值小于80的事实表明,FM-n系列的紫外吸收频率与结构之间的定量关系可以用扩大同系方程来近似地表示。但在FNE-n系列中,由于氰基的存在,用扩大同系方程计算得到的λ值与实验值偏差较大,?     

定量共振论与MO的关系——奇共轭烃的激发态

Quantified resonance theory (QRT) involving the use of weighting has been applied to ionization potential, electron affinity, energy of the lowest π→π~* transiton, charge density and bond order in excited state for odd π hydrocarbon radicals, anions and cations, the QRT results are in remarkable agreement with HMO, the heteroatom effects on these properties obtained by QRT are in full accord with PMO. Moreover QRT gives a simple rule for estimating whether odd nonalternant hydrocarbons containing a 5-or 7-membered ring have NBMO or not.     

Lucas sequences and Fibonacci triads of graphs in PMO calculation on the charge-transfer bands of a series of EDA complexes: Correlation with experimental and AM1 results

The use of Lucas sequences and Fibonacci triads of graphs in a complete PMO calculation on a series of phenols is shown. The results were correlated with charge-transfer absorption maxima of a series of molecular EDA complexes of p-chloranil with these phenols as donors. The correlation brings out the PMO parameters in a straightforward way. The graph theoretical results are also shown to correlate well with the donor ionization potentials calculated by the AM1 method, and this correlation yields a value of the sp²-C Coulomb integral, α, which agrees well with the one obtained from photoelectron spectroscopic results. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 817–825, 1997     

Finite lifetime effects on the polarizability within time-dependent density-functional theory

We present an implementation for considering finite lifetime of the electronic excited states into linear-response theory within time-dependent density-functional theory. The lifetime of the excited states is introduced by a common phenomenological damping factor. The real and imaginary frequency-dependent polarizabilities can thus be calculated over a broad range of frequencies. This allows for the study of linear-response properties both in the resonance and nonresonance cases. The method is complementary to the standard approach of calculating the excitation energies from the poles of the polarizability. The real and imaginary polarizabilities can then be calculated in any specific energy range of interest, in contrast to the excitation energies which are usually solved only for the lowest electronic states. We have verified the method by investigating the photoabsorption properties of small alkali clusters. For these systems, we have calculated the real and imaginary polarizabilities in the energy range of 1-4 eV and compared these with excitation energy calculations. The results showed good agreement with both previous theoretical and experimental results.     

Internal rotation and rotational isomerism in substituted ethanes

The types of potential energy curves of internal rotation in substituted ethanes were studied. Formulas for the calculation of the energy differences in rotational isomers and of the potential barriers to internal rotation in these derivatives were obtained by Bernstein's method. As a rule, the calculated results are in agreement with experiment.     

有机试剂结构与性质的研究(X)——偶氮苯衍生物结构与吸收光谱的研究

本文应用PPP-SCF-CI法计算了偶氮苯衍生物的结构,发现偶氮苯衍生物波长最大的吸收峰(相应于电子从基态向第一激发态跃迁)是分子内荷移光谱,这些吸收峰的计算值与实验值完全一致.此外,还根据PPP计算结果研究了取代基对吸收光谱的影响.     

Cross sections and rate coefficients for electronic excitation of the triplet states of the hydrogen molecule in different vibrational levels

Cross sections for the excitation of the triplet state of H₂ from different vibrational levels of the ground electronic state have been calculated by using the Gryzinski approximation. The results for the ground vibrational level are in satisfactory agreement with the corresponding values obtained by the quantum mechanical close coupling method. The calculated cross sections have been used to generate rate coefficients for the excitation of the triplet states by using a self-consistent electron energy distribution function, obtained by numerical integration of the Boltzmann equation. The results show a strong increase of the different rate coefficients with increasing the vibrational quantum number.