【作者】 张志强；

【导师】 张浩力；

【作者基本信息】 兰州大学 ， 化学·有机化学， 2024， 硕士

【摘要】 有机余辉材料,包括有机室温磷光材料、热激活延迟荧光材料和有机长余辉材料,具有寿命长、斯托克斯位移大、信噪比高和内量子产率高等特点,在光电器件、生物成像、防伪、加密和信息储存等方面有着广泛的应用潜力,是近年的研究热点。以硼酸为主体的复合有机室温磷光材料,其基本策略是通过热处理将芳基硼酸或芳基羧酸客体分子嵌入硼酸基质,从而获得长寿命室温磷光。目前,运用该策略已获得数例长寿命室温磷光材料。但是,仍然缺乏定向选择客体以获得具有超长寿命室温磷光材料的明确策略。本论文设计了分别以3种羟基苯硼酸和3种氰基苯硼酸为客体的室温磷光材料,通过比较由不同客体所制备的室温磷光材料寿命的差别来阐明客体取代基对硼酸基质室温磷光材料寿命的影响,从而得出定向选择客体以获取超长室温磷光的策略。热激活延迟荧光材料,特别是具有圆偏振发光性质的热激活延迟荧光材料,因其在圆偏振有机发光二极管方面的应用前景,成为当前研究的热点。本论文以联萘酚为骨架,通过二苯胺及其衍生物的引入制备了具有圆偏振发光性质的热激活延迟荧光材料,实现了发光颜色从黄绿色到橙红的改变。长余辉材料,特别是具有手性的长余辉材料,因其广泛的应用潜力而受到关注,但平面手性有机长余辉分子却少见报道。因此,本论文以[2.2]环仿为骨架设计了平面手性长余辉分子,并进行了合成。论文主要内容如下:第一章,本章对室温磷光以及热激活延迟荧光的发光原理,关键参数及研究现状进行了总结,阐明了论文选题的依据。第二章,本章工作以羟基硼酸和氰基硼酸为客体,以硼酸为主体,在两种温度下制备了12种长余辉室温磷光材料,通过稳态瞬态荧光光谱仪测定了其寿命及固态光致发光量子产率,并研究了其长寿命发光的机理。首先以酚羟基处于不同位置的三种羟基苯硼酸为客体,在两种温度下制备了六种室温磷光材料。通过对比同一客体,经过不同温度的热处理所得到的室温磷光材料的余辉寿命长短,分析产生不同寿命的原因,阐明温度升高对此类室温磷光材料寿命的影响。通过比较经过相同处理温度,羟基处于不同位置时所制得的磷光材料的寿命,分析其产生不同寿命的原因,阐明羟基的供电子作用对材料磷光的影响。其次,以氰基位置不同的三种氰基苯硼酸为客体,在两种温度下制备了六种室温磷光材料。通过对比同一客体,经过不同温度的热处理所得到的室温磷光材料的余辉寿命长短,分析产生不同寿命的原因,阐明温度升高对此类室温磷光材料寿命的影响。通过比较经过相同处理温度,氰基处于不同位置时所制得的磷光材料的寿命,分析其产生不同寿命的原因,阐明氰基的吸电子作用对材料磷光的影响。然后通过对羟基苯硼酸和氰基苯硼酸所制备的12种室温磷光材料的寿命及量子产率的差异的分析,得出客体取代基吸电子效应可提升材料磷光寿命,客体取代基位置对于寿命也有较大影响,温度的提升有利于量子产率的提升。最后,提出了定向选择客体以获得超长寿命和高量子产率室温磷光材料的策略。第三章,以联萘酚为轴手性骨架,通过苯环固定酚羟基,同时在苯环上引入二苯胺及其衍生物,制备了3对固态发光量子产率高的轴手性热激活延迟荧光分子(R/S-BIBA,R/S-BIBR,R/S-BICN)。本章工作通过圆二色光谱仪验证了已制备的三对对映体的手性,通过圆偏振荧光光谱仪测定了其圆偏振发光的性质、通过稳态瞬态荧光光谱仪测定了其寿命及固态光致发光量子产率并且通过理论计算对其TADF性质进行了研究。R/S-BIBA,R/S-BIBR,R/S-BICN分别呈橙红色、黄色和黄绿色,均具有较高的固态光致发光量子产率。增二苯胺上取代基的吸电子能力使荧光颜色从橙红色改变为黄色和黄绿色,显示了该分子可通过改变取代基的供电子效应和吸电子效应实现全色圆偏振热激活延迟荧光的潜力。第四章,以[2.2]环蕃为骨架,设计了全新的平面手性长余辉分子,并开展了合成工作。[2.2]环蕃自身无手性,通过在两个苯环上引入不同基团产生了手性。通过反应产生的外消旋体可通过与手性樟脑磺酸反应得到非对映异构体,然后通过柱层析分离。所拆分的分子通过圆二色光谱仪验证了其确为对映体,并且在后续反应中手性得以保持。第五章,对工作进行了展望并阐述了本工作的不足。更多还原

【Abstract】 Organic afterglow materials,including Organic Room Temperature Phosphorescence(RTP)materials,Thermally Activated Delayed Fluorescence(TADF)materials and Organic Long Persistent Luminescence(OLPL)materials,have the characteristics of long lifetime,large Stokes shift,high signal-to-noise ratio,and high Internal Quantum Efficiency(IQE).They have broad application potential in optoelectronic devices,biological imaging,anti-counterfeiting,encryption,and information storage,and have become a research hotspot in recent years.The RTP materials which boric acid is used as host and guests are embedded into boric acid matrix though a heating process to gain long lifetime RTP has been demonstrated as an effective strategy,but there is no clearly strategy to select guests to gain ultralong lifetime RTP till now.Take the papers published into consideration,the electronwithdrawing effect of the substituents of guests was considered as the key point to gain ultralong lifetime RTP for this system.Thus,Hydroxyphenylboronic acid and Cyanophenylboronic Acid were used as guests to prepare RTP materials.The strategy to gain ultralong lifetime RTP has been proposed by compared the different lifetimes of RTP materials using different substituents or substitution positions of guests.Thermally activated delayed fluorescence materials,especially those with circularly polarized luminescence properties,have become a hot research topic due to their widespread application in circularly polarized organic light-emitting diodes.1,1’-binaphthyl-2,2’-diol was used as the backbone and achieved a change in luminescence color from yellow green to orange red through the introduction of diphenylamine and its derivatives.Long persistent luminescence materials,especially those with chirality,have attracted attention due to their wide application potential.However,there are few reports on planar chiral long persistent luminescence(LPL).Therefore,we designed planar chiral long persistent luminescence molecules using [2.2]paracyclophane(PCP)as the framework and synthesized them.The main content of the paper is as follows:In Chapter 1,the luminescence principles,key parameters,and research status of room temperature phosphorescence and thermally activated delayed fluorescence were summarized,and the basis for the topic selection of this paper was elucidated.In Chapter 2,12 types of long afterglow room temperature phosphorescent materials were prepared.Hydroxyphenylboronic acid and Cyanophenylboronic Acid are used as guests and boric acid was used as host.Firstly,three hydroxyphenylboronic acids were used as guests to prepare six room temperature phosphorescent materials at two different temperatures.By comparing the afterglow lifetimes of room temperature phosphorescent materials prepared from same guests after the heating treatment at different temperatures.Analyzing the reasons for different lifetimes,and elucidating the effect of temperature increase on the lifetimes of these room temperature phosphorescent materials.By comparing the lifetimes of phosphorescent materials prepared by different guests which hydroxyl group is at different positions after the same heating temperature.The reasons for different lifetimes of these RTP materials have been analyzed,and the effect of electron donating effect of hydroxyl group on the phosphorescent lifetimes of these materials has been elucidated.Secondly,three different cyanophenylboronic acids were used as guests to prepare six room temperature phosphorescent materials at two different temperatures.By comparing the lifetimes of phosphorescent materials with guests that cyano group are at different positions after the same heating temperature.The reasons for their different lifetimes have been analyzed,and the influence of electron withdrawing effect of cyanide groups on material phosphorescence.Then,by analyzing the differences in lifetime and quantum yield of 12 room temperature phosphorescent materials prepared by hydroxyphenylboronic acid and cyanophenylboronic acid,it was found that the electron withdrawing effect of guest substituents can enhance the phosphorescence lifetime of the materials,and the position of guest substituents also has a significant impact on the lifetime.The increase in temperature is conducive to the improvement of quantum yield.Finally,a strategy of directional selection of guests was proposed to obtain room temperature phosphorescent materials with ultra long lifetimes and high quantum yieldsIn Chapter 3,Three pairs of circularly polarized thermally activated delayed fluorescence molecules(R/S-BIBA,R/S-BIBR,R/S-BICN)with high quantum yield were prepared.These molecules were prepared by using 1,1’-binaphthyl-2,2’-diol as the axial chiral backbone,then immobilizing phenolic hydroxyl groups by benzene and introducing diphenylamine and its derivatives onto the benzene.In this chapter,the chirality of these three prepared enantiomers was verified using a circular dichroism spectrometer.The circularly polarized luminescence properties were determined using a circularly polarized fluorescence spectrometer,and the lifetime and solid-state photoluminescence quantum yield were measured using a steady-state transient fluorescence spectrometer.The TADF properties were studied through theoretical calculations.R/S-BIBA,R/S-BIBR,and R/S-BICN are orange red,yellow,and yellow green respectively,all of which have high solid-state photoluminescence quantum yields.Enhancing the electron withdrawing ability of the functional group on diphenylamine changes the fluorescence color from orange red to yellow and yellow green,indicating that the molecule can achieve full color circularly polarized thermally activated delayed fluorescence by changing the electron donating and electron withdrawing effects of the substituent.In Chapter 4,novel planar chiral long afterglow molecules were designed using[2.2] paracyclophane as the raw material.The chirality is generated by introducing different functional groups on two benzene rings,as the [2.2] paracyclophane themselves have no chirality.The racemate produced by the reaction can be separated by using chiral camphor sulfonic acid to react with our products to obtain non enantiomers,which are then separated by column chromatography.The separated molecules were confirmed to be enantiomers by circular dichroism spectroscopy,and their chirality was maintained in subsequent reactions.The final step of synthesis is still incomplete.In Chapter 5,outlook on the shortcomings of my work and the scalability of the experiment have been provided.更多还原