【作者】 袁慎峰；

【导师】 吕德伟； 陈志荣；

【作者基本信息】 浙江大学 ， 化学工程及技术， 2003， 博士

【摘要】 为提高用ZINDO／S方法预测染料分子吸收光谱的准确度，本文提出了一种新的思路，即暂且抛弃某一固定的OWF_π-π（π-π重叠加权因子，ZINDO／S方法中的一个可调参数）值对大多数化合物的适用性，把OWF₍π-π看作是分子共轭程度的一个量度。对同一系列的化合物，首先根据其吸收光谱的实测值选择OWF_π-π，使吸收光谱计算值与实测值相吻合，而后利用回归方法揭示OWF_π-π与分子构型参数的关系。 本文的研究结果表明，对于不同结构类型的染料分子，影响OWF_π-π的主要分子构型参数也不相同。根据本文的研究，主要影响参数包括以下几种：（1）偶合组分和重氮组分之间的夹角α对OWF_π-π有较大的影响，OWF_π-π随α的增大而线性减小，如某些偶氮苯衍生物、氨基嘧啶类染料母体、偶合组分和重氮组分之间夹角α变化较大的活性染料等。（2）给电子取代基或吸电子取代基的电荷对OWF_π-π有较大的影响，OWF_π-π随电荷的变化而线性变化，如某些偶氮苯衍生物、吡啶酮类染料母体、硝基二苯胺类化合物、偶合组分和重氮组分之间夹角α变化不大的活性染料、1,4—二（取代）氨基蒽醌衍生物等。（3）键长和共轭双键数对OWF_π-π有较大的影响，OWF_π-π随键长（如平面型的偶氮苯衍生物、菁类和氧杂菁类等）和双键数（如共轭烯烃类、β—胡萝卜素和番茄红素等）的变化而线性变化。（4）取代基类型和取代基位置对OWF_π-π有较大的影响，如萘醌类发色母体、蒽醌类发色母体等。（5）对酞菁类这一特殊类型的发色体，配位氮原子平均电荷和中心原子电负性对OWF_π-π有较大的影响，OWF_π-π随它们的增大而线性增大。上述结果均能从量子化学的角度进行解释。本文的研究结果还表明，用OWF_π-π与分子构型参数的关系可对吸收半峰宽进行初步的预测。 综上可见： （1）将OWF_π-π作为分子共轭程度的量度是合适的，将简单母体OWF_π-π与分子构型参数的关系用于同类发色母体吸收半峰宽的预测和同一系列复杂染料分子吸收光谱的计算也是可行的，因此，本文的研究为提高吸收光谱预测的准确度提供了一种新的思路。 （2）各种发色母体OWF_π-π与分子构型参数之间确实存在某种关系，这种关系不仅可以用量子化学理论进行较好的解释，而且在同一系列中具有一定的外推适用性，因而大大地提高了吸收光谱预测的准确度。 （3）对染料吸收光谱的准确预测，可从本质上揭示分子结构与吸收光谱之间的关系，为染料分子结构设计提供理论依据；此外，对染料样品剖析也将起到很大的帮助作用。更多还原

【Abstract】 In order to improve the prediction accuracy of the absorption spectroscopy of dyes by ZINDO/S method, a new idea was introduced in this thesis, that is, OWF?(the simplification of π-π overlap weighting factor’, one of the adjustable parameters in ZINDO/S method) was considered as a measurement of the conjugation extent of a molecule, rather than a certain fixed value applicable to all molecules. For compounds of the same kind, firstly, the value of OWFπ-π was so determined that the calculated absorption maximum could coincide with observed ones well, then, the method of regression was used to reveal the relationship between OWFπ-π and molecular conformation parameters.The results of this study showed that the primary conformation parameter affecting OWFπ-πwas different for different kinds of molecules. According to this study, OWFπ-πwas affected by the following conformation parameters. (1) The angle between diazo component and coupling component affected OWFπ-πgreatly for some azobenzene derivatives, aminopyrimidine derivatives and some reactive dyes, in this instance, OWFπ-π decreased linearly with the increase of the angle. (2) The charges on the substituents affected OWFπ-π greatly for some azobenzene derivatives, pyridone derivatives, nitrodiphenylamine derivatives, some reactive dyes and 1, 4-diamino anthraquinone derivatives, in this instance, OWFπ-π changed linearly with the change of the charges. (3) The length of certain bond(s) and the number of conjugate double-bond affected OWFπ-π greatly, OWFπ-π changed linearly with the change of bond length (for planar azobenzene derivatives and cyanine derivatives) and the change of conjugate double-bond number (for conjugate alkene, p-carotene and lycopene). (4) The type and position of substituents affected OWFπ-π greatly for naphthoquinone and anthraquinone derivatives. (5) The charges on coordinated bonded nitrogens and the electronegativity of central atom affected OWFπ-π greatly for phthalocyanine compounds, OWFπ-π increased linearly with the increase of the charges and the electronegativity. All the above phenomena could be explained in terms of quantum chemistry. In this study, it was also shown that the absorption half-bandwidth could be predicted roughly according to the relationship between OWFπ-π and molecular conformation parameters.In conclusion: (1) It is appropriate to consider OWFπ-π as a measurement of the conjugation extent of amolecule and it is feasible to predict the absorption half-bandwidth and absorption maximum of complex dyes according to the relationship between OWFπ-π and molecular conformation parameters obtained from simple molecules of the same kind. Consequently, a new thought to improve the prediction accuracy of the absorption spectroscopy is presented in this dissertation.(2) There is indeed some relationship between OWFπ-π and molecular conformation parameters. The obtained relationship not only could be explained in terms of quantum chemistry, but also could be extrapolated in the same series of molecules. Therefore, the prediction accuracy of absorption spectroscopy could be improved evidently.(3) The accurate prediction of absorption spectroscopy could on one hand, reveal the relationship between molecular conformation and absorption spectroscopy, and on the other, offer a theoretical basis for the design of dye molecules. Furthermore, it could also give assistance in the analysis of dye samples.更多还原