【作者】 王鹏程；

【导师】 陆明；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2013， 博士

【摘要】 硝化反应是工业化生产的有机合成方法中极其重要的一类。一方面,其产物可广泛地应用于炸药、推进剂、化工原料、医药和农药等许多领域；另一方面,芳烃硝化机理的研究对亲电取代反应基础理论发展起了很大的作用。本文主要探索了多种新型绿色的催化硝化反应体系,并借助于量化手段,从理论方面,包括硝化反应机理和部分硝基化合物的合成路线等,进行进一步研究。为了适应日益严峻的环境问题,改善工业生产中严重的污染问题,本文探索了多种绿色催化硝化体系,包括：1)纳米氧化物负载的杂多酸催化；2)酸性离子液体/N2O5体系；3)表面活性剂做相转移催化剂；4)多种高比表面的复合型固体酸催化。每个催化体系的总体研究程序如下,先通过不同的表征手段确定合成的催化剂,然后对催化硝化的反应条件进行优化,最后对催化体系的适用性和催化剂的循环次数进行考察。结果表明,这些催化体系均能减少甚至避免混酸的使用,减少废酸的排放。大部分体系还可以改变硝化产物中异构体的比值,单取代烷基苯的对邻比可以提高到1：1,单取代卤代苯的对邻比可以提高到5：1,部分二取代苯的选择性可超过9：1。改善选择性,最终可获得具有更高商业价值的硝化产物。采用量化模拟的手段,本文对理论方面的研究主要在两个方面,一是对部分催化硝化过程进行机理的研究,二是对部分合成的硝基化合物进行合成路线的研究。首先,为了深入的了解催化硝化的反应过程,本文借助Gaussian量子化学模拟软件,尝试通过计算模拟来研究其催化反应机理。在对表面活性剂催化二取代芳烃的反应模拟后发现,影响硝化产物中异构体分布的因素主要有两个,一个是空间位阻,另一个是芳烃电荷或自旋电子的分布情况,选择性是两者相互制约的结果,而通过改变其中任一因素,即很有可能使选择性发生较大改变。而在固体酸催化单取代芳烃的硝化过程中,因为空间影响相对较小,本文着重研究了固体酸催化剂中过渡金属原子与芳烃的相互作用。结果表明,这些金属原子改变了芳烃上的电荷或自旋电子的分布,最终导致选择性发生明显的变化。接着,围绕2,6-二氨基-3,5-二硝基吡啶和2,6-二氨基-3,5二硝基-1-氧-吡嗪(LLM-105)的制备合成与性能应用进行了深入的研究,先是优化了2,6-二氨基-3,5-硝基吡啶的合成条件,产率可达90%以上；因其可以做为多种潜在含能材料的中间体,进一步研究了其还原成2,3,5,6-四氨基吡啶的方法。而在对LLM-105的研究中,改进了LLM-105的合成方法,将总产率提高到了65%。借助与Gaussian着重比较了两条合成路线的不同,并进一步研究了各个基团之间的相互作用,结果表明,涵盖整个分子的大共轭体系是该物质有很好性能的关键。更多还原

【Abstract】 Nitration is one of the most important organic reactions in industry. It has a wide application in many areas, such as explosive, propellant, chemical intermediates, medicine and pesticide. On the other hand, the mechanism research on aromatic plays an important role in the development of electrophilic substitution theory. Here, we mainly studied the synthesis method of nitro-compounds (mainly nitration), reaction mechanism and pre-evaluating the property of part of these compounds.To solve the more and more serious environmental problem and modify the pollution in industrial production, we discovered several green nitration system:1) Nano metal oxides supported heteropoly acid;2) Acidity ionic liquid/N2O5system;3) surfactant as phase-transfer catalyst;4) various of modified solid acid with high surface. The general research process in each catalytic system was as follow:first part was the characterization of these novel catalysts with different method; secondly, optimize the reaction condition with this catalytic system; finally, investigate the applicability and recycle performance of the catalyst. The results showed that all these catalytic systems could significantly reduce or avoid the using of liquid acid. Besides that, most catalytic systems could change the isomer distribution in nitro-products, the para/ortho ratio of mono-alkylbenzene could be improved to1:1, para/ortho ratio of mono-halogenobenzen would be improved to5:1, part of the disubstituted aromatic could reach9:1. By modifying the selectivity, higher commercial value compounds would be obtained.With quantum chemistry simulation method, the theoretical study mainly focused on two areas:one is the mechanism research of above nitration process with different catalytic system; the other is the evaluation of the property of synthesized or designed nitro-compounds.First, to understanding the nitration mechanism, we attempted to simulate the catalytic process by computer with quantum chemistry software Gaussian. With the simulation result of disubstituted aromatic nitration with surfactant, two main factors that affect the product distribution were found:one was sterical exclusion; the other was charge or spinning electron distribution in benzene ring. Selectivity was the mutual restraint result. Change either factor, the selectivity might be influenced. In the study of nitration of monosubstitute aromatic with solid acid, the sterical exclusion was small enough that we could focus on the other factor. We mainly calculated the interaction between transition metal and aromatic. The results showed that this interaction can modify the distribution of charge or spinning electron and thus leaded to a significant change in selectivity.Next, we studied the preparation and property of2,6-diamino-3,5-dinitropyrdine (LLM-105) and2,6-diamino-3,5-dinitropyrazine-l-oxide. First, the synthetic condition of2,6-diamino-3,5-dinitropyrdine was optimized and got an excellent yield over90%; then, because it was also a potential intermediate for several new and excellent energetic materials, we studied its reduction to2,3,5,6-tetraamineopyridine. In the research of LLM-105, the synthetic method was improved and the yield reached65%. Two different synthetic routes were compared with Gaussian, and the function of each group was discussed in detail. The result showed that π-conjugate of electron cloud involving the whole molecule was the key of its high stability and excellent performance.更多还原