| Abstract | 吩嗪类化合物具有诸多优异性质，已被广泛用于生化检测、有机半导体器件、光催化、药物、染料等领域。与此同时，有关吩嗪类化合物的合成研究也是硕果累累，比如已实现利用生物合成方法对吩嗪类抗菌农药进行商业生产、开发出了包括机械化学合成法在内的众多用于吩嗪化合物合成的化学合成方法等等。但吩嗪类化合物的相关研究还存在以下亟待改进和解决的问题：1.部分吩嗪化合物价格昂贵，对其在生化检测等领域上的应用产生不利影响。比如， 5,14-二氢-5,7,12,14-四氮杂并五苯（DHTAP）是一种在有机半导体器件研究领域常用的吩嗪化合物，其250 mg的售价超过10000元。2.已报道的用于吩嗪化合物合成的无溶剂法存在反应时间长、需惰性气体保护等不足。3.已有文献报道部分吩嗪化合物具有光化学活性，但目前已报道的具有光化学活性的吩嗪化合物种类较少。4.以2-氨基-3-羟基吩嗪和2,3-二氨基吩嗪为代表的吩嗪类化合物具有自组装性质，但通过自组装形成的形貌较为单一，多为微、纳米尺度上的线状或者带状。因此，发展新的制备方法、挖掘吩嗪化合物的性质、探索部分吩嗪化合物在生化检测等领域的应用潜力仍具有重要意义。本毕业论文致力于开发针对吩嗪化合物的简单廉价合成方法，研究部分吩嗪化合物在光化学、自组装等方面的性质，探索了部分吩嗪化合物在生化检测等领域的应用潜力。
本毕业论文共分为六章。
第一章：对吩嗪化合物进行了简要概述。着重介绍了吩嗪化合物在性质、应用以及合成方面的研究进展。
第二章：受冰盘这一自然现象的启发，建立了一种运动界面诱导、反应协同的微纳颗粒自组装方法，并基于该方法在振荡的液面上成功地制备出梭形微米颗粒。邻苯二胺（oPD）在盐酸中被双氧水氧化产生2-氨基-3-羟基吩嗪（HAP）。在静置状态下，反应产生的HAP逐渐形成微、纳米尺度上的一维线状、带状材料。在振荡状态下，反应中产生的一维材料在反应液表面自组装形成梭形微米结构，而后续产生的HAP在梭形微米结构上不断析出，使该结构成为稳定的颗粒。增加转速，梭形颗粒变小，且其尺寸更均一。在一定范围内延长反应时间会显著增加梭形微米颗粒的厚度。梭形颗粒内部结构会随着溶剂水的挥发发生改变。静态下产生的颗粒的形貌会影响自组装颗粒的形貌：对于在静态下形成近球形颗粒的物质，其在振荡条件下的液面上形成盘状或碗状颗粒。梭形颗粒在水面可以通过自组装形成稳定的花状结构，并以此为单元进而形成更大尺度上的有序结构。此外，鉴于HAP在分析检测、抗癌活性物质的合成等领域的潜在应用价值，本章所报道的HAP的合成方法也具有实用价值。
第三章：研究了5,12-二氢苯并[b]吩嗪（DHBP）的光活化自催化氧化，以及该光化学反应在有机合成和分析检测上的应用潜力。以最佳发射波长位于365&ndash516 nm的LED作为光源，溶液中的DHBP会发生光活化氧化，产生苯并[b]吩嗪（BP）。DHBP的反S型浓度-时间曲线表明了自催化的存在，而LED的发射光谱与DHBP和BP的吸收光谱的重叠结果则进一步证实了自催化的存在。DHBP荧光发射光谱与BP吸收光谱存在重叠，这表明DHBP的荧光可以被BP吸收并通过自催化过程被用于DHBP的氧化。BP自身在溶液中也会发生光解反应，但当DHBP存在时，BP可以通过催化DHBP的氧化而避免自身被氧气氧化。基于此，我们开发了一种利用太阳能的绿色合成方法，并将该方法用于DHBP类分子的氧化。2,2,6,6-四甲基哌啶氧化物（TEMPO）的还原产物能够在光照条件下经BP催化恢复为TEMPO，这说明BP具有作为光催化剂的潜力。另外，基于DHBP和BP的荧光颜色具有显著差异，我们考察了DHBP作为荧光探针在双通道实时监测溶液中溶解氧上的应用潜力。
第四章：以邻苯二胺为原料，基于一步溶剂热法制备了5,14-二氢喹喔啉并[2,3-B]吩嗪（即5,14-二氢-5,7,12,14-四氮杂并五苯，DHTAP），并研究了DHTAP在多色荧光成像等方面的应用潜力。基于控制变量法研究了溶剂种类、反应温度、时间、氧气量等因素对DHTAP产率的影响。延长反应时间、升高反应温度均有利于DHTAP的生成，但考虑到时间成本以及聚四氟乙烯内衬的使用条件，反应时间的延长以及反应温度的升高均是有限的。氧气是反应的氧化剂，反应中通过控制反应釜内衬中的空气体积来控制参与反应的氧气的量。适度过量的氧气有利于提高DHTAP的产率。DHTAP的激发光谱波长范围较宽，这使其可与多种荧光材料混合得到具有双发射荧光的材料组合。基于此，我们用DHTAP和吖啶橙的混合溶液对HeLa细胞进行染色，实现了双色同时成像。溶剂热法制备DHTAP的研究为后续DHTAP的合成方法研究提供了几个有参考意义的信息：1. 一定条件下，以廉价的邻苯二胺和空气中的氧气就可以实现DHTAP的合成2. DHTAP具有较好的热稳定性以及一定的抗氧气氧化能力。
第五章：建立了一种NaCl辅助的无溶剂法，并以邻苯二胺为原料，在空气气氛中，高效、廉价、快速地制备了DHTAP。在320 °C下加热经盐酸酸化的邻苯二胺13 min，DHTAP的产率可达36%。在相似条件下，以2,3-二氨基吩嗪（或者2-氨基-3-羟基吩嗪）和邻苯二胺为原料，反应时间可缩短至5 min，DHTAP的产率可达99.5%。传热的快慢影响反应的时间，减小反应管的内径可以显著缩短反应时间。无机盐对反应具有显著影响。NaCl的使用显著提高了DHTAP的产率常见无机盐中，KCl对应的反应结果与NaCl的相当，其它常见无机盐对应的DHTAP的产率均小于1%。无机盐在热稳定性、对盐酸的吸附能力以及诱导二维结构生长的能力上的差异可能是造成DHTAP产率显著不同的原因。盐酸的使用也是实现DHTAP高效合成的重要原因之一。以硫酸、磷酸、硝酸、水、NaOH、氨水等替代盐酸，DHTAP的产率均小于1%。鉴于DHTAP的高售价以及广泛的用途，本章建立的DHTAP的合成方法具有一定的实用价值。
第六章：基于上一章建立的NaCl辅助合成法，高效制备了多种氮杂并苯分子，分析了部分氮杂苯不能用该方法合成的原因，研究了所制备化合物在比率检测pH上的应用潜力。原料和产物的热稳定性是决定目标化合物能否合成的重要因素之一。分子构型优化结果表明，产物分子中的氮杂并苯结构均呈现平面构型，该结果与DHTAP的结构优化结果一致，表明氮杂并苯结构呈现平面构型有利于分子稳定。部分分子中取代基的引入破坏了氮杂并苯结构的平面构型，这会降低该分子的稳定性，进而降低产率。部分产物发生了质子转移重排，这可能是由重排后分子的HOMO和LUMO的能级差较大造成的。所制备的氮杂并苯分子均具有pH响应性。其中，1,3-二氢-2H-咪唑并[4,5-b]吩嗪-2-酮展现出了作为pH荧光探针的良好应用前景：对pH的检测区间位于6.4&ndash8.5，该区间与生理活动中多种体液的pH变化区间重叠其荧光颜色由酸性环境中的绿色变为碱性环境中的橘色，便于人眼观察。 |
| Other Abstract | Phenazines have many excellent properties and have been widely used in biochemical analysis, organic semiconductor devices, photocatalysis, therapy, dyes, and so on. At the same time, the research on the synthesis of phenazines is also fruitful: the commercial production of phenazine antibacterial pesticides has been realized by using the biosynthesis method, and many chemical synthesis methods, including mechanochemical synthesis, have been developed for the synthesis of phenazines. However, there are still some problems to be solved in the research of phenazines: 1. Some phenazines are expensive, which has a negative impact on their application in biochemical detection and so on. For example, 5,14-dihydro-5,7,12,14-tetraazapentacene (DHTAP) is a phenazine derivative commonly used in the field of organic semiconductor device, and its 250 mg price exceeds 10,000 yuan. 2. The solvent-free methods reported for the synthesis of phenazines have shortcomings such as long reaction time and inert gas protection. 3. It has been reported in the literature that some phenazines have photochemical activity, but the total number of phenazines with photochemical activity reported so far is relatively small. 4. The phenazines represented by 2-amino-3-hydroxyphenazine and 2,3-diaminophenazine have self-assembling properties. However, the morphology formed by self-assembly is relatively simple, mostly in the form of lines or bands on the micro and nano scales. Therefore, it is still of great significance to develop new preparation methods, explore the properties of phenazine compounds, and explore the application potential of some phenazines in biochemical detection and other fields. This thesis is devoted to developing a simple and cheap synthesis method for phenazines, studying the properties of some phenazine compounds in photochemistry, self-assembly and other aspects, and exploring the application potential of some phenazine compounds in biochemical detection and other fields.
This thesis contains six chapters.
Chapter 1: Phenazines were introduced briefly. The research progress of phenazines was summarized based on their properties, applications and synthesis.
Chapter 2: Inspired by the natural phenomenon of "ice disk", the method of micro/nano-particles self-assembly induced by moving interface and coordinated by reaction was established. Based on this method, shuttle-like microparticles were successfully prepared on the oscillating liquid surface. O-phenylenediamine (oPD) was oxidized by hydrogen peroxide in hydrochloric acid to produce 2-amino-3-hydroxyphenazine (HAP). In the static state, the HAP produced by the reaction gradually forms one-dimensional linear and band-shaped materials on the micro and nano scales. In the oscillating state, the initially produced one-dimensional materials formed shuttle-like self-assemblies on the surface of the reaction solution, and with the continuous precipitation of HAP, the shuttle-like assemblies became stable particles. Increasing the oscillating speed, the shuttle-like particles became smaller and more uniform. The extension of the reaction time significantly increased the thickness of the particles. The internal structure of the particles changed with the evaporation of the water. The morphology of the self-assembled particles was influenced by the morphology of the particles produced under static state: when the near spherical particles were formed under static state, the disk or bowl shaped particles were formed on the liquid surface under oscillating condition. The shuttle-like particles could form a stable flower-like structure by self-assembly on the water surface, and further formed an ordered structure on a larger scale. In addition, in view of the application value of HAP in the fields of biochemical detection and synthesis of anticancer active substances, the synthesis method of HAP reported here also was also valuable.
Chapter 3: We investigated the photoactivated autocatalytic oxidation of 5,12-dihydrobenzo [b] phenazine (DHBP) and the application potential of this photochemical reaction in organic synthesis and biochemical detection. Under the illumination of the LED with the optimal emission wavelength at 365&ndash516 nm, DHBP in solution underwent photoactivated oxidation to produce benzo[b]phenazine (BP). The inverse S concentration-time curve of DHBP indicated the presence of autocatalysis, and the overlap between the emission spectrum of LED and the absorption spectrum of DHBP and BP further confirmed the autocatalysis. The fluorescence emission spectrum of DHBP overlapped with the absorption spectrum of BP, which indicated that the DHBP fluorescence could be absorbed by BP and used for the oxidation of DHBP through an autocatalytic process. BP also underwent photolysis in solutionbut when DHBP was present, BP could catalyze the oxidation of DHBP to avoid its own oxidation. Based on this, we developed a green synthesis method using solar energy and applied the method to the oxidation of DHBP and its derivatives. The reduction product of 2,2,6,6-tetramethylpiperidinooxy (TEMPO) could be restored to TEMPO catalyzed by BP under light conditions, which showed that BP had the potential as a photocatalyst. In addition, based on the significant difference in fluorescence color between DHBP and BP, we investigated the application potential of DHBP as a fluorescent probe in the dual-channel real-time monitoring of the dissolved oxygen in solutions.
Chapter 4: Using o-phenylenediamine (oPD) as the raw material, we prepared 5,14-dihydroquinoxalino[2,3-b]phenazine (5,14-dihydro-5,7,12,14-tetraazapentacene, DHTAP) by one-step solvothermal method, and studied the application potential of DHTAP in cell imaging. Based on the controlling variable method, we studied the factors that affect the yield of DHTAP. The extension of the reaction time and the increase of the reaction temperature were conducive to the formation of DHTAP, but considering the cost of time and the application conditions of the Teflon lining, the extension of the reaction time and the increase of the reaction temperature were limited. Oxygen was the oxidant of the reaction, and the amount of oxygen in the reaction was controlled by controlling the volume of air in the Teflon lining. A moderate excess of oxygen was beneficial to increase the yield of DHTAP. The wavelength range of DHTAP's excitation spectrum was wide, which made it possible to mix with a fluorescent material to obtain a dual emission fluorescence. Based on this, we stained HeLa cells with a mixed solution of DHTAP and acridine orange to achieve the dual-color simultaneous imaging. The solvothermal preparation of DHTAP provides several meaningful information for the subsequent research on the synthesis of DHTAP: 1. Under some conditions, the synthesis of DHTAP could be achieved with the inexpensive oPD and oxygen in the air2. DHTAP had good thermal stability and anti-oxidation ability.
Chapter 5: We have established a NaCl-assisted solvent-free method and used oPD as the raw material to prepare DHTAP efficiently, cheaply and quickly in an air atmosphere. By heating o-phenylenediamine acidified with hydrochloric acid at 320 °C for 13 min, the yield of DHTAP reached 36%. Under similar conditions, using 2,3-diaminophenazine (or 2-amino-3-hydroxyphenazine) and oPD as raw materials, the reaction time was shortened to 5 min, and the yield of DHTAP reached 99.5%. The speed of heat transfer affected the reaction time, and the reaction time could be significantly shortened by using the reaction tube with a smaller inner diameter. Inorganic salts significantly affected the synthesis of DHTAP. The use of NaCl significantly improved the yield of DHTAPamong common inorganic salts, the reaction result corresponding to KCl was comparable to that of NaCl, and the yield of DHTAP corresponding to other common inorganic salts was less than 1%. The difference among inorganic salts in thermal stability, adsorption capacity of hydrochloric acid, and the ability to induce the growth of two-dimensional materials could be the reason for the significant difference in the yield of DHTAP. The use of hydrochloric acid was also one of the reasons for the high yield of DHTAP. When hydrochloric acid was replaced by sulfuric acid, phosphoric acid, nitric acid, water, NaOH or ammonia, the yield of DHTAP was less than 1%. In view of the high price and wide application of DHTAP, the synthetic method of DHTAP established in this chapter was a practical method worth promoting.
Chapter 6: Based on the NaCl-assisted synthesis method established in the previous chapter, we prepared several azaacenes, analyzed the reasons why some azaacenes could not be synthesized by this method, and studied the application potential of the prepared compounds in the ratiometric fluorescence detection of pH. The thermal stability of raw materials and products was one of the important factors that determined whether the target compound could be synthesized. The results of geometry optimization show that the azaacene structures in the product molecules all were planar, which were consistent with the structural optimization results of DHTAP. The above results indicated that the planar azaacene structure was conducive to keeping the molecule stable. The introduction of substituents on some molecules destroyed the planar configuration of the azaacene, which reduced the stability of the molecule and thus reduces the yield. The introduction of substituents in some molecules destroyed the planar configuration of the azaacene, which reduced the stability of the molecule and further reduced the yield. One of the azaacenes had undergone prototropic rearrangement, which might be caused by the larger energy gaps between HOMO and LUMO of the molecule after rearrangement. The prepared azaacenes all behaved excellent pH-responsive. Among them, 1,3-dihydro-2H-imidazo[4,5-b]phenazin-2-one showed a good application prospect as a pH fluorescent probe: The pH detection range was 6.4&ndash8.5, which overlapped with the pH change range of various body fluidsIts fluorescent color changed from green in acidic environment to orange in alkaline environment, which was easy for human eye to observe. |
