蓝光萘酰亚胺发光材料的合成与表征

通过在4位引入不同芳香基团,采用Suzuki和Stille偶联反应,设计与合成了一系列新型1,8-萘酰亚胺类荧光染料,并研究了它们的紫外-可见吸收、荧光发射和电化学行为等光物理性质。这些化合物在甲苯中均发射蓝色荧光,最大吸收和荧光发射峰分别在357～378和423～451nm之间,且随着芳香基团供电性增强,吸收和荧光发射波长发生红移。芳香基团的结构对化合物的发光效率影响很大,其中,取代基为甲氧基苯的化合物具有最高的荧光量子效率,可达0.98,而取代基为噻吩的化合物荧光量子效率最低,只有0.17。电化学循环伏安研究表明该类化合物具有较高的电子亲合力,不同芳香基团的引入只影响化合物的被占分子轨道(HOMO)能级,而对化合物的最低空分子轨道(LUMO)能级没有影响,即LUMO能级由1,8-萘酰亚胺单元决定。     

N-苯甲酰胺基取代的双吲哚马来酰亚胺类化合物的合成与荧光性质研究

以琥珀酰亚胺为原料,经溴代、吲哚加成、与水合肼反应、酰基化和烷基化等反应,设计合成了6a～6c和7a～7b共5个新型N-苯甲酰胺基取代的双吲哚马来酰亚胺类化合物,其结构经IR,1H NMR和HRMS等进行了表征,并研究了该类化合物的紫外、荧光性能和热性质.研究表明,N-苯甲酰胺基取代的双吲哚马来酰亚胺类化合物的紫外吸收光谱在360～400和450～500 nm显示两个主要吸收峰,将N原子甲基化和苄基化后,紫外吸收峰波长发生红移.以化合物紫外最大吸收波长为激发波长,目标化合物的荧光发射光谱在560～620 nm有最大发射峰,7a有最大的荧光量子产率,7a在不同溶剂中随溶剂极性的增大,量子产率没有明显的变化规律,讨论了化合物的结构对荧光性能的影响.热学性质研究表明,化合物7a和7b的玻璃化转变温度(Tg)分别为116和80℃,目标化合物的分解温度接近400℃.     

新型中位取代七甲川菁染料的合成及光稳定性研究

本文合成了两种新型中位取代近红外七甲川菁染料,采用核磁1 HN-MR和HRMS质谱对其结构进行了表征.并测试了染料在不同溶剂中的吸收光谱和荧光发射光谱性质.染料3b、3c在甲醇中的最大吸收波长和最大荧光发射波长分别为677/790nm和647/786nm,斯托克斯位移分别为113 nm、139nm.经过光降解实验测试得到3种染料3a—3c在乙醇中的光降解速率常数分别为1.21×10-3 mol/min、1.81×10-3 mol/min和2.14×10-3 mol/min.循环伏安法测得染料3a—3c的氧化电位分别在0.729V、0.624V和0.598V.光降解实验表明:七甲川菁染料中位亚甲基链上吸电基取代增强染料光稳定性,供电基取代减弱染料的光稳定性;供-吸电子能力强弱决定了染料的光稳定性强弱;同时中位氯原子取代与共轭链上的氢键作用有利于染料的稳定性增强,中位氮原子取代无法形成很好的氢键作用,不利于染料稳定性的提高.     

溶剂极性效应和pH效应对萘二酰亚胺型荧光探针荧光光谱影响的研究

萘二酰亚胺类化合物是新的抗病毒前体之一,在生物化学和医学领域的应用近来引起广泛注意[1].这类化合物具有独特的荧光特性[2],可用于核酸损害机理的研究,是典型的外源型核酸荧光探针之一.因此,研究这类探针的荧光光谱特性对核酸化学的研究将提供重要信息.本文研究了三种新型荧光探针N-(羟乙基)-1,8-萘二酰亚胺(NI1),2-(1,8-萘二酰亚胺基)乙酸(NI2)和6-(1,8-萘二酰亚胺基)正己酸(NI3)在不同极性溶剂中的荧光光谱性质.实验表明,随着溶剂极性的增大,NI型荧光探针的荧光发射峰值发生了明显的红移,荧光强度变化的总体是增大的(表1),其Stock位移(荧光的最大发射峰波长值与最大吸收峰波长值之差)符合Lippert线性方程,如图1所示.     

萘酰亚胺类荧光染料及共聚型荧光聚氨酯乳液的合成与性能

首先以4-溴-1,8-萘酐、2-氨基-1,3-丙二醇和甲醇钠为原料, 经亚胺化和取代两步反应合成出4-甲氧基-N-(2-羟基-1-羟甲基乙基)-1, 8-萘酰亚胺(MHHNA)活性荧光染料, 然后将其作为扩链剂通过相反转自乳化法制备出了共聚型荧光聚氨酯(PU) (PU-MHHNA)乳液, 并分别采用核磁共振氢谱(¹H NMR)、核磁共振碳谱(¹³CNMR)、元素分析、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)吸收光谱、荧光光谱、粒度分析、氙灯老化等方法对所得荧光染料的化学结构、PU乳液及乳胶膜的性能进行了表征. 结果表明, MHHNA和PU-MHHNA的荧光量子产率分别为0.73 和0.92, MHHNA的用量对所得PU乳液的胶体性质没有明显影响. PU-MHHNA的丙酮溶液在UV-Vis 吸收光谱上的最大吸收波长(λ_max)为360.6 nm, 在荧光光谱上的最大激发波长(λ_ex)和最大发射波长(λ_em)分别为362和435 nm. 随着温度的升高, PU-MHHNA的荧光强度逐渐降低. PU-MHHNA乳胶膜的耐光色牢度和耐溶剂色牢度均明显高于共混型荧光聚氨酯(PU/MBNA)乳胶膜.     

可溶性苝四羧酸二酰亚胺发光材料的合成及表征

以苝四酸酐为原料合成了1,7-二溴-3,4,9,10-苝四酸酐(PeryBr₂)、N,N′-二(十二烷基)-1,7-二溴-3,4,9,10-苝四羧酸二酰亚胺(DD-PeryBr₂)和N,N′-二(十二烷基)-1,7-二对叔丁基苯氧基-3,4,9,10-苝四羧酸二酰亚胺(DD-PeryBp₂) 3种苝四羧酸二酰亚胺类化合物,并对其结构和性能利用紫外-可见吸收光谱、傅立叶红外光谱、核磁共振、质谱、热分析和荧光光谱测试技术进行了表征和测试。 结果表明,DD-PeryBp₂能很好的溶于甲苯、氯仿、四氢呋喃等常用有机溶剂。 紫外可见最大吸收波长和荧光最大发射波长分别为548和576 nm。 DD-PeryBp₂具有很好的热稳定性,质量损失5%时的温度为433 ℃。     

新型水溶性不对称五甲川吲哚菁染料的合成、荧光性能及荧光标记

合成了枝状聚乙二醇醚链取代的新型不对称五甲川吲哚菁荧光染料,利用1H NMR、HRMS等技术手段表征了化合物的结构,并测定了染料的荧光性能、光稳定性,标示了牛血清白蛋白。结果表明,该染料的最大吸收波长为657 nm,最大荧光发射波长为671 nm,荧光量子产率为0.24,经过8 h的光照反应,染料有4.4%产生光降解,溶于水,n(染料)∶n(牛血清白蛋白)=2∶1时,标记蛋白质的染料/蛋白质(D/P)值达1.57。     

新型不对称五甲川菁染料的合成及光稳定性能研究

合成并表征了5种不对称五甲川菁染料,染料在甲醇中的最大吸收和荧光光谱在646—666nm之间.光降解实验证明两端取代基结构呈不对称的染料,其光稳定性明显高于两端取代基结构对称的染料.染料荧光光谱和pH值的关系表明,染料中引入苯环取代基可以增强染料在酸性或碱性溶液中的稳定性.     

N,N′-二-(2-吡啶基)苝四羧酸二酰亚胺的合成及性能研究

合成了N,N′ 二 (2 吡啶基)四羧酸二酰亚胺,并纯化、调晶.对产物进行了元素分析和IR光谱研究(环状二酰亚胺的CO以双峰1708.8cm-1、1664 5cm-1).α晶型产物溶液的紫外可见光谱(最大吸收波长为526.00nm)和荧光光谱(最大发射波长为538.0nm)存在很好的镜像对称关系.薄膜紫外可见光谱图在450—570nm范围内,α晶型比β晶型有较强的吸收峰.X粉末衍射也反映出α晶型在2θ为25.5°、26.3°上的衍射峰强度分别为1954、2603.α、β晶型分别作为电荷产生材料制得的功能分离型有机光导体,在光源波长λ=532nm曝光下,测得含α的感光体达到饱和电位的时间45s、半衰曝光量5.7μJ/cm2、残余电位22V等数据.测得含β的感光体达到饱和电位的时间49s、半衰曝光量9.9μJ/cm2、残余电位22V等性能数值.     

BODIPY-吡咯类荧光染料的合成及光谱识别性能

采用Knoevenagel反应以氟化硼配位二吡咯甲川类荧光染料BODIPY(4,4-difluoro-4-bora-3a,4adiaza-s-indacene)为母体,经吡咯甲醛或杯吡咯甲醛合成了四个BODIPY荧光染料1a~1d,用MS,NMR和元素分析进行结构确证。考察了它们的紫外吸收光谱与荧光发射光谱,结果表明1a~1d具有较高的摩尔吸光系数,在BODIPY母环的3,5位双取代物(1c和1d)相对于单取代物(1a和1b)其最大吸收波长和发射波长分别红移了约90nm和80nm,说明BODIPY-吡咯衍生物中共轭程度增强,光谱出现红移。阴离子识别研究表明,1b和1d能够与Cl-形成多重氢键,导致吸收光谱红移和荧光猝灭。     

Core-tetrasubstituted naphthalene diimides: synthesis, optical properties, and redox characteristics

2,3,6,7-tetrabromonaphthalene dianhydride has been synthesized by the bromination of naphthalene dianhydride with dibromoisocyanuric acid in excellent yield. The condensation of this dianhydride with 2,6-diisopropylaniline yielded the corresponding tetrabromo-substituted naphthalene diimide (NDI), which is a versatile precursor for the synthesis of core-tetrafunctionalized NDIs. Nucleophilic substitution of tetrabromo NDI with alkoxy, alkylthio, and alkylamino nucleophiles afforded a series of core-tetrasubstituted NDI chromophores that complete the series of previously reported di- and trifunctionalized NDI derivatives. The effects of electronic nature and number of core substituents on the optical and electrochemical properties of NDIs have been investigated by UV-vis and fluorescence spectroscopy and cyclic voltammetry. The absorption maxima (629-642 nm) of tetraamino NDIs are strongly bathochromically shifted compared to those of other core-functionalized NDIs.     

Femtosecond time-resolved photophysics of 1,4,5,8-naphthalene diimides

The photophysical properties of a tetrahedral molecule with naphthalene diimide (NDI) moieties and of two model compounds were investigated. The absorption and fluorescence spectra of dialkyl-substituted NDI are in agreement with literature. While the absorption spectra of phenyl-substituted molecules are similar to all other NDIs, their fluorescence showed a broad band between 500 and 650 nm. This band is sensitive to the polarity of the solvent and is attributed to a CT state. The absorption spectra and lifetime (10+/-2 ps) of the electronically excited singlet state of a dialkyl-substituted NDI was determined by femtosecond transient absorption spectroscopy, and the latter was confirmed by picosecond fluorescence spectroscopy. Nanosecond flash photolysis showed the subsequent formation of the triplet state. The presence of a phenyl substituent on the imide nitrogen of NDI resulted in faster deactivation of the singlet state (lifetime 0.5-1 ps). This is attributed to the formation of a short-lived CT state, which decays to the local triplet state. The faster deactivation was confirmed by fluorescence lifetime measurements in solution and in a low-temperature methyl-tetrahydrofuran glass.     

Fluorimetric determination of magnesium by ternary complex formation with pyridoxal nicotinylhydrazone and amines

The synthesis, characteristics and analytical applications of pyridoxal nicotinylhydrazone are described. This compound reacts with magnesium(II) in the presence of ammonia, ethylenediamine or pyridine, to produce a 1:1:1 Mg(II)—pyridoxal nicotinylhydrazone—amine fluorescent complex (λ_ex 395 nm, λ_em 480 nm). A fluorimetric method is proposed for the determination of magnesium(II) (20–100 ng ml^-1 in the solution measured); isobutanol is used to extract the complex, reducing the number of interferences.     

Photoinduced Color Change and Photomechanical Effect of Naphthalene Diimides Bearing Alkylamine Moieties in the Solid State

Photoinduced color change of naphthalene diimides (NDIs) bearing alkylamine moieties has been observed in the solid state. The color change is attributed to the generation of a NDI radical‐anion species, which may be formed through a photoinduced electron‐transfer process from the alkylamine moiety to the NDI. The photosensitivity of NDIs is highly dependent on the structures of the alkylamine moieties. Crystallographic analysis, kinetic analysis, UV/Vis/NIR spectroscopic measurements, and analysis of the photoproduct suggested that a radical anion was formed through an irreversible process initiated by proton abstraction between an amine radical cation and the neutral amine moiety. The radical anions formed stacks including mixed‐valence stacks and radical‐anion stacks, as shown by the broad absorption bands in near‐IR spectra. These photosensitive NDIs also showed crystal bending upon photoirradiation, which may be associated with a change in the intermolecular distance of the NDI stacks by the formation of monomeric radical anions, mixed‐valence stacks, and radical‐anion stacks.     

Fluoranthene and its π-extended diimides: Construction of new electron acceptors

3,4,8,9-Fluoranthenetetracarboxylic diimides (FDI) are first synthesized as stable yellow compounds by the Diels-Alder (DA) reaction of maleic anhydride and acecyclone derivative bearing an acenaphthylene imide unit and subsequent imidations. An X-ray crystallographic analysis of di(N-octyl)FDI derivative reveals the planar fluoranthene diimide π -system. The cyclic voltammograms of FDIs shows considerably high electron affinity. Moreover, its π -extended analogue involving an anthracene unit (DAAI) was also prepared by the DA reaction of acenaphthylene-3,4-dicarboxylic imide with o-xylylene derivative. The compound exhibits long wavelength absorption and intense fluorescence with moderate solvatofluorochromism (Δλ_EM?=?41?nm). Theoretical calculations based on density function theory (DFT) were performed to characterize the electronic feature of these diimides.     

Modulating Electron Transfer in a Simple Bichromophoric System Employing Axial-Ligation as an Organising Precept

A naphthalene diimide acceptor 1 bearing a pyridine group linked directly (a series) or through a —CH₂CH₂— spacer (b series) coordinated axially to a metallotetraarylporphyrin (MP) undergoes fast photoinduced electron transfer (in the case of MP = Zn(II)TTP) while the kinetically more stable ruthenium complexes (MP = Ru(CO)TPP) have been used to illustrate the correlation between the distance of probe protons from the porphyrin plane and the change in chemical shift (Δδ) upon coordination. Changes in the emission spectra at 650 nm (λ _ex= 400 nm) upon the addition of Zn(II) ions and/or 1b to TTPH₂ can be interpreted in a truth table to illustrate a NAND gate.     

Naphthalenediimides with Cyclic Oligochalcogenides in Their Core

Naphthalenediimides (NDIs) are privileged scaffolds par excellence, of use in functional systems from catalysts to ion channels, photosystems, sensors, ordered matter in all forms, tubes, knots, stacks, sheets, vesicles, and colored over the full visible range. Despite this extensively explored chemical space, there is still room to discover core-substituted NDIs with fundamentally new properties: NDIs with cyclic trisulfides (i.e., trisulfanes) in their core absorb at 668 nm, emit at 801 nm, and contract into disulfides (i.e., dithietes) upon irradiation at <475 nm. Intramolecular 1,5-chalcogen bonds account for record redshifts with trisulfides, ring-tension mediated chalcogen-bond-mediated cleavage for blueshifts to 492 nm upon ring contraction. Cyclic oligochalcogenides (COCs) in the NDI core open faster than strained dithiolanes as in asparagusic acid and are much better retained on thiol exchange affinity columns. This makes COC-NDIs attractive not only within the existing multifunctionality, particularly artificial photosystems, but also for thiol-mediated cellular uptake.     

Synthesis and properties of novel soluble poly(amide‐imide)s with different pendant substituents

Two types of novel fluorinated diimide‐diacid monomers—[2,2′‐(4,4′‐(3′‐methylbiphenyl‐2,5‐diyl)bis(oxy)bis(3‐(trifluoromethyl)‐4,1‐phenylene))bis(1,3‐dioxoisoindoline‐5‐carboxylic acid)] (III) and [2,2′‐(4,4′‐(3′‐(trifluoromethyl)biphenyl‐2,5‐diyl)bis(oxy)bis(3‐(trifluoromethyl)‐4,1‐phenylene))bis(1,3‐dioxoisoindoline‐5‐carboxylic acid)] (IV)—were respectively designed and prepared by the condensation of diamines I and II with two molar equivalents of trimellitic anhydride. From both diimide‐diacids, two series of novel poly(amide‐imide)s (PAIs) (IIIa–IIIe and IVa–IVe) bearing different pendant groups were prepared by direct polymerization with various aromatic diamines (a–e). All the PAIs had a high glass transition temperatures (T_gs, 232–265 °C), excellent thermal stability (exhibiting only 5% weight loss at 493–542 °C under nitrogen) and good solubility in various organic solvents due to the introduction of the bulky pendant groups. The cast films of these PAIs (80–90 μm) had good optical transparency (73–81% at 450 nm, 85–88% at 550 nm and 87–89% at 800 nm) and low dielectric constants (2.65–2.98 at 1 MHz). The spin‐coated films of these PAIs presented a minimum birefringence value as low as 0.0077–0.0143 at 650 nm and low optical absorption at the near‐infrared optical communication wavelengths of 1310 and 1550 nm. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3243–3252     

Ratiometric Fluorescence Imaging of Cellular Polarity: Decrease in Mitochondrial Polarity in Cancer Cells

Mitochondrial polarity strongly influences the intracellular transportation of proteins and interactions between biomacromolecules. The first fluorescent probe capable of the ratiometric imaging of mitochondrial polarity is reported. The probe, termed BOB, has two absorption maxima (λ_abs=426 and 561 nm) and two emission maxima—a strong green emission (λ_em=467 nm) and a weak red emission (642 nm in methanol)—when excited at 405 nm. However, only the green emission is markedly sensitive to polarity changes, thus providing a ratiometric fluorescence response with a good linear relationship in both extensive and narrow ranges of solution polarity. BOB possesses high specificity to mitochondria (R_r=0.96) that is independent of the mitochondrial membrane potential. The mitochondrial polarity in cancer cells was found to be lower than that of normal cells by ratiometric fluorescence imaging with BOB. The difference in mitochondrial polarity might be used to distinguish cancer cells from normal cells.     

Catalytic Oxidation of Indigo Carmine in the Presence of Silver Nanoparticles: Application to Groundwater Analysis

The oxidation of indigo carmine by potassium hexacyanoferrate(III) is catalyzed by trace of silver nanoparticle (AgNP). The reaction is followed UV‐Vis absorption spectrophotometrically by measuring the change in the absorption spectra (λ_max 612 nm). The catalytic oxidation reaction is used for the quantification of indigo carmine. The calibration graph was linear in the concentration range 50 nM—1.8 μM of indigo carmine. The variables affecting the method have been optimized. The method is applied to the determination of indigo carmine in groundwater samples with the satisfactory results.