固液态均荧光发射的四苯乙烯基衍生物的合成

为了打破传统荧光材料的聚集荧光淬灭(ACQ)的应用限制,通过共价键连接聚集诱导发光(AIE)分子与平面ACQ分子,可以构建在溶液中和固态下都具有荧光发射特性的化合物。分别通过多步反应合成了带有烷基硫醚的萘酰亚胺衍生物3和连接炔吡啶的四苯乙烯衍生物7。化合物3和化合物7通过酰胺缩合,合成了一种四苯乙烯-萘酰亚胺二联体化合物8,化合物8兼具ACQ和AIE分子的特性。结果表明：溶液状态下化合物8具有蓝色荧光发射,其最大发射峰位于452 nm,固态下为黄绿色荧光,最大发射峰位于487 nm。利用三氟乙酸对其荧光进行调控能够实现CIE色坐标为(0.33, 0.32)的单分子白光发射。     

取代基效应对喹啉腈AIE荧光性能的研究

吡喃腈(DCM)类化合物作为传统的荧光染料, 其本身具有聚集荧光淬灭(Aggregation caused quenching, ACQ)的现象. 通过对吡喃腈母体进行结构修饰, 合成了一类具有长波长、聚集诱导发光(Aggregation-induced emission, AIE)的喹啉腈(QM)衍生物, 该类化合物在良溶剂中呈现弱荧光, 但在聚集态和固态时荧光增强. 并进一步研究了取代基效应对这类AIE化合物荧光性能的影响, 卤素原子的引入使得聚集态荧光基本保持在561~571 nm之间, 但荧光量子效率变化很大, QM-Br的Φ_F值最大(13.9%), QM-F次之(8.7%), QM-I最小(3.4%). 给电子单元可与QM母体单元形成D-π-A结构, 其增强的推拉电子效应延长了聚集态波长, 同时能级带隙变窄. 取代基效应的研究有助于理解AIE化合物聚集微环境的变化, 为进一步发展近红外AIE荧光染料及其生物应用打下良好的基础.     

含四苯基乙烯的炔酮衍生物的设计合成、聚集诱导发光性质及其对Pd2+的选择性荧光检测

聚集诱导发光（AIE）材料吸引了许多光电器件和生物荧光技术领域的科学家的关注.对聚集诱导发光化合物构效关系的深入理解对于设计新材料至关重要.在本工作中,基于经典的AIE基元四苯基乙烯,设计并合成了一系列具有AIE性质,含不同电子给体/受体取代基的炔酮衍生物.对这一系列化合物的光物理性质进行了系统研究并分别探讨了取代基团对发光波长、发光效率和AIE性质的影响.它们的聚集态最大发射波长位于511～565 nm,在四氢呋喃/水混合溶液中的荧光量子产率可达31%.在末端苯环上的电子给体/受体取代基团会降低聚集态的发光效率,而引入硝基取代基则会在发射波长红移的同时,显著猝灭荧光.最为重要的是,这些化合物结构中的炔酮基元可以在一系列金属离子中选择性地与Pd²⁺配位,猝灭纳米聚集体的发光,并有望作为一个有效的Pd²⁺荧光传感器.     

TPE核的螺旋手性

正2001年,唐本忠等基于多苯环取代的噻咯衍生物在良溶剂中不发光或发光微弱,而在聚集状态下荧光大大增强的现象,率先提出了"聚集诱导发光(aggregation-induced emission,AIE)"的概念~1,经过大量实验验证和理论模拟,他们提出了分子内运动受限是导致化合物产生AIE现象的主     

基于三苯胺的荧光探针设计、合成与应用研究进展

螺旋桨结构的三苯胺荧光团既能作为强的电子供体,又能作为潜在的聚集诱导发光(AIE)骨架.同时,三苯胺衍生物很容易通过简单的反应进行结构修饰,如醛基、氨基、硼酸基、卤素、乙炔基等取代的三苯胺能够发生缩合反应或偶联反应等,进一步功能化.因此,功能性三苯胺类化合物被广泛用于太阳能电池、荧光染料、固态发光材料和荧光探针的分子设...     

新型固态荧光增强的萘酰亚胺衍生物的合成与发光行为

萘酰亚胺及其衍生物由于其独特的光物理性质、光稳定性和电子接受能力而广泛应用于荧光传感器、光电材料等领域。本文设计并合成了一种新型固态荧光增强的萘酰亚胺衍生物,其结构经¹H NMR、 ¹³C NMR、 MS和IR表征,并研究了该化合物的固态和溶液发光行为。结果表明：该化合物不仅在稀溶液中表现出可调谐的可见光发射,而且表现出固态荧光增强,这种行为与ACQ和AIE发色团明显不同。     

二苯乙烯基蒽聚集诱导发光材料体系的研究进展

具有聚集诱导发光(AIE)性质的有机荧光分子由于其扭曲的分子构型,在聚集态或固态表现出显著增强的荧光发射,避免了传统有机荧光分子的浓度猝灭现象,因而在光电器件、生物传感等领域有着广泛的应用.本文着重介绍了具有AIE性质的二苯乙烯基蒽(DSA)衍生物及其在高效固态发光材料、刺激响应材料、生物成像和生物与化学传感等领域的研究进展.     

四苯基乙烯衍生物光物理和光化学研究

设计合成了一个四苯基乙烯衍生物Model-TPE,该化合物具有典型的聚集诱导发光（AIE）特性。¹HNMR、质谱以及高效液相色谱研究表明,有氧条件下Model-TPE经紫外光照射发生关环反应,生成二苯基取代菲衍生物,取代和未取代苯环侧关环反应得到异构体产物,提出了光氧化关环反应机理。本工作对TPE衍生物在发光及传感领域的应用有一定的指导意义。     

多芳基丁二烯的聚集诱导发光性质及其应用

聚集诱导发光（Aggregation-induced emission，AIE）是指分子在稀溶液（分散态）中发光微弱或不发光，而在聚集态时具有荧光或者荧光发射增强的现象。AIE现象有效地解决了绝大多数荧光材料聚集诱导猝灭（Aggregation-caused quenching，ACQ）的难题，扩大了荧光材料（聚集体状态下）在有机光电器件、化学传感、生物传感等领域的应用。 开发新的简易AIE基元，并阐明机理、实现应用，已成为目前AIE研究领域最主要的任务。本论文首次建立以六苯基丁二烯（HPB）为AIE基元的新体系，展现出在多个领域中的潜在应用价值。主要内容： 1.通过对带有不同长度烷基链和取代基（溴，甲氧基）HPB衍生物AIE性质的研究，表明取代基推、拉电子能力较弱时，对AIE性质影响较小；由于单晶结构堆砌松散，从而呈现力致变色现象，并且可以通过“研磨-熏蒸”的方式实现力致变色的多次循环。 2.成功合成并经柱色谱一次性分离提纯三种含醛基HPB异构体，3种异构体EE-、EZ-和ZZ-HPB-CHO依次呈现黄光、绿光和青光，均具有典型的AIE性质。其中ZZ-HPB-CHO由于扭曲的结构和较为疏松的堆积，具有力致变色的性能，并且在有机试剂的熏蒸下可以实现“研磨-熏蒸”和“蓝移-恢复”的多次循环。 3.基于醛基的活性，通过与路易斯酸B (C₆F₅)₃配位作用以及B (C₆F₅)₃可催化醛基和羟基的半缩醛反应，实现红-黄-青的循环转化，这是目前报道中实现三色转换较为简单的方法。在这可重复循环过程中，每一化合物均保持典型的AIE或者AEE性质。 4.由醛基与丙二腈的反应，合成了ZZ-HPB-CN。由于CN基团的引入，使ZZ-HPB-CN发射波长红移。实验结果表明，试纸基底（滤纸）提供热诱导结晶作用，使ZZ-HPB-CN产生有序排序，与此同时，在紫外光的诱发下发生内环化反应，从而使ZZ-HPB-CN试纸荧光强度随着温度的升高而增强，实现越热越亮的效果，并在30～70℃范围内荧光强度呈现与温度的线性关系，可以称之为光/热诱导荧光增强现象（LTEE），这是第一个报道的对温度正响应的具有AIE性能的固态响应器件。 5.通过利用醛基与茚二酮（ID）的反应，合成了具有典型AIE性质的EE-HPB-ID化合物。作为探针，其对3-硝基-1,2,4-三唑-5-酮（NTO）具有荧光点亮型响应，并且肉眼即可观测到荧光强度的改变。该检测在水/THF体系中，检测限可以达到7 nM。此外，该化合物对于其他大部分多氮唑化合物均具有点亮型响应，即使硝基等强荧光猝灭性基团的存在也不会影响检测效果，而对常见的其他爆炸物和咪唑没有响应，表现出对多氮唑的广谱性检测能力。     

三苯基咪唑衍生物的聚集诱导发光性质及其细胞成像应用

聚集诱导发光(AIE)材料在生物医学领域有很大优势,尤其为生物成像研究开启了新局面.通过2,4,5-三苯基咪唑衍生物与1,4-二溴丁烷/1-溴丁烷亲核取代反应,合成了2个丁烷桥联的双咪唑衍生物及2个1-位丁基取代的单咪唑衍生物. 4个产物都表现出优异的AIE性质,其中含有甲氧基助色团的衍生物具有更长的发射波长.机理研究表明限制扭曲的分子内电荷转移是这类结构具有AIE活性的原因,因此, 2-位强吸电子芳基是它们具有AIE活性的决定因素.此外,咪唑环1-位取代基的空间效应对AIE也非常重要,因为较大体积的1-位取代基使分子呈扭曲构象,从而限制聚集态π-π堆积作用.最后,研究了1-位丁基取代的单咪唑衍生物的细胞染色和成像性能,结果显示二者在蓝色、绿色及红色通道都表现出不错的荧光成像能力,但在不同颜色通道观察到的细胞被染色区域不完全相同.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.