新型萘四甲酸酯的合成及其光谱性质与液晶行为

以四辛基溴化铵为相转移催化剂,以1,4,5,8-萘四甲酸为原料,分别与溴代丁烷和溴代辛烷反应制备了1,4,5,8-萘四甲酸丁酯和1,4,5,8-萘四甲酸辛酯.采用紫外可见光谱和荧光光谱等测试技术研究了2种化合物的光谱性质.结果表明,2种化合物在溶液中有可能形成激基缔合物,采用DSC和偏光显微镜测试技术研究了其热行为和液晶性质.结果发现,2种化合物均表现出热致液晶性.     

甲氧基萘类荧光单体的合成及其光谱研究

以4-溴-1,8-萘二甲酸酐为原料,合成了2种水溶性甲氧基萘类荧光单体,测定了它们的激发光谱和发射光谱.运用密度泛函(DFT)及含时密度泛函(TDDFT)方法预测的荧光发射光谱与实验结果符合得较好.     

大共轭芳香基桥联双杯[4]芳烃的合成与染料配合性能

杯[4]-1,3-二氨基衍生物3分别与均苯四甲酸酐、1,4,5,8-萘四甲酸酐、3,4,9,10-苝四甲酸酐反应,以"2+2"的模式合成了三种大共轭芳香基桥联的双杯[4]芳烃4、5和6,产率为60%~70%.液液两相萃取实验表明化合物4~6对染料分子橙黄I(OI)和维多利亚蓝(VB)有较好萃取能力,化合物6对OI的萃取率达88.3%.紫外配合光谱、紫外滴定工作曲线和配合质谱均表明,主客体在DMSO溶液中形成1∶1的配合物,化合物6对OI的配合常数达2.80×105L·mol-1.化合物4~6的染料配合能力强弱次序为化合物4化合物5化合物6,这表明桥联芳香共轭基团在配合过程中有重要作用.     

新型1,4,5,8-萘酰亚胺类衍生物的合成

以1,4,5,8-萘四甲酸二酐(1)和2-乙基己胺(2)为原料,设计并合成了3种新型的1,4,5,8-萘酰亚胺类衍生物,其结构经1H NMR,IR和MS表征。中间体N-(2-乙基己基)-萘-1,8-二甲酸单酐-4,5-单甲酰亚胺的最佳反应条件为:19.7 mmol,n(1)∶n(2)=1.1∶1.0,以醋酸锌为催化剂,在DMF(20 mL)中于140℃反应15h,收率25%。     

1,8-双(邻羧基苯甲酰)萘酸酐的合成

研究了1,8-双(邻甲酸酐苯甲酰基)萘的合成方法.从7,8-苊二酮出发,与邻溴甲苯的格氏试剂生成7,8-(邻甲基基)苊二醇,用重铬酸钾把羟基氧化成酮.并形成与羰基相邻的羧基.这一反应使在苯环上与羰基相邻的羧基处于有利位置,以使两个羧基脱水成酸酐.     

基于萘二酰亚胺衍生物的给受体共晶的分子自组装和荧光变化

由两种或两种以上不同组分通过π-π相互作用、电荷转移和氢/卤键等非共价相互作用形成的有机共晶体,因其在有机光电子领域中的应用而受到广泛关注.本文通过溶液共结晶的方法制备了三种电荷转移共晶体,以晕苯和芘作为给体,萘二酰亚胺衍生物N,N'-二甲基-1,4,5,8-萘四甲酸二酰亚胺(N,N'-dimethyl-1,4,5,8...     

基于1，4，5，8-萘四羧酸原位合成的钡配合物的结构、对芳香胺的检测及其作为纳米BaCO3的前驱体

以1,4,5,8-萘四羧酸为原料,在溶剂热条件下原位反应合成得到一个具有3D拓扑结构的发光钡基金属有机骨架(MOF):[Ba(dna)(H₂O)₂]n(1,H₂dna=1,8-萘二甲酸酐-4,5-二羧酸),并通过单晶X射线衍射、元素分析、热重分析和粉末X射线衍射技术对其进行表征。结构分析表明,1包含一个π共轭基团和酸酐基团的有机配体dna^2-,荧光和紫外研究表明其能灵敏地检测溶液中的芳香胺,可能是MOF结构中配体的酸酐基团和氨基之间的反应驱动的,这大大提高了荧光发射强度,并达到裸眼可见的颜色变化。此外,以配合物1为前驱体在中等温度下直接煅烧制得了单一晶型的纳米BaCO₃颗粒。     

1,8-萘酰亚胺类衍生物的合成及细胞活性研究

以4-溴-1,8萘二甲酸酐作为先导化合物,通过氨解、亲核取代合成了9个1,8-萘酰亚胺类衍生物,通过质谱(MS)、核磁共振氢谱(1H-NMR)、核磁共振碳谱(13C-NMR)表征其结构,采用CCK8法检测目标化合物对乳腺癌MCF-7、肺癌H460、肝癌HepG2的细胞活性.结果表明,9个衍生物中目标化合物3b的体外抗肿...     

萘二酰亚胺同分异构体化合物的设计合成及其单分子导电性能研究

本文设计合成了两个4-甲硫基苯乙炔基取代的1,4,5,8-萘二酰亚胺(1,4,5,8-NDI)和1,2,5,6-萘二酰亚胺(1,2,5,6-NDI)同分异构体化合物1和2,并用紫外-可见吸收光谱、电化学等手段研究了其物理化学性质.化合物1和2结构上的差异导致其物理化学性质以及单分子器件性能表现出差异.密度泛函理论(DF...     

新型手性季鏻盐的合成

以(S)-联萘酚为原料,与三氟甲磺酸酐反应制得联萘酚三氟甲磺酸酯(2);2在Ni(dppp)Cl2催化下与碘甲烷格氏试剂反应得2,2’-二甲基联萘(3);3经溴代反应得2,2’-二溴甲基联萘4;4与1,3-双(二苯基膦)丙烷(dppp)在甲苯中回流合成了一个新型的联萘酚衍生的双中心手性季鏻盐,其结构经1H NMR,31P NMR和FT-IR表征。     

An effective and regioselective bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride using tribromoisocyanuric acid

A highly efficient and cost-effective reagent for the bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride under mild reaction conditions is reported. Bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride using tribromoisocyanuric acid (TBCA) in concentrated H₂SO₄ is very effective and regioselective. 1,4,5,8-Naphthalenetetracarboxylic dianhydride was brominated smoothly under optimized reaction conditions to give mono-, di- and tetra-brominated products in good to excellent yields using TBCA. As a proof of principle, the potential of this bromination methodology is demonstrated by converting brominated naphthalenetetracarboxylic dianhydrides into N-imide and core functionalized 1,4,5,8-napthalenetetracarboxylic diimides by treating with n-butylamine to yield corresponding mono-, di- and tetra-(n-butylamino)-naphthalene diimides in good yields in one-step reactions.     

Simple and Efficient Method for Obtaining Fluorene and Spirobifluorene Bromide Derivatives

A mild, simple, and efficient synthetic procedure for the preparation of 2-monobromo-, 2,7-dibromo-, and 2,2′,7,7′-tetrabromo-substituted spirobifluorene derivatives and their key intermediates, 2-monobromo- and 2,7-dibromo-substituted fluorene compounds, has been developed. The oxidative bromination of fluorene and spirobifluorene was achieved using NaBr/H₂O₂ as the bromine source. High conversion of the starting materials was achieved together with good selectivities under optimized reaction conditions.     

Efficient Synthesis of a New Family of 2,6-Disulfanyl-9-selenabicyclo[3.3.1]nonanes

The efficient synthesis of a new family of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonanes in high yields has been developed based on 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion generated from bis-isothiouronium salt of 2,6-dibromo-9-selenabicyclo[3.3.1]nonane. The derivatives of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonane containing alkyl, allyl and benzyl moieties have been prepared in 90–99% yields by nucleophilic substitution of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion with alkyl, allyl and benzyl halides. The reaction of nucleophilic addition of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion to alkyl propiolates afforded 2,6-di(vinylsulfanyl)-9-selenabicyclo[3.3.1]nonanes. The conditions for regio- and stereoselective addition of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion to a triple bond of alkyl propiolates have been found. To date, not a single representative of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonanes has been described in the literature.     

Reactivities of carboxyalkyl-substituted 1,4,5,8-naphthalene diimides in aqueous solution

A series of water-soluble 1,4,5,8-naphthalene diimide derivatives has been prepared and their redox and photophysical properties characterized. From laser flash photolysis studies, the triplet excited state of N,N'-bis[2-(N-pyridinium)ethyl]-1,4,5,8-naphthalene diimide (NDI-pyr) was found to undergo oxidative quenching with the electron donors DABCO, tyrosine, and tryptophan as expected from thermodynamics. Interestingly, the reactivities of naphthalene diimides (NDI) possessing alpha- and beta-carboxylic acid substituents (R = -CH2COO-, -C(CH3)2COO-, and -CH2CH2COO-) were strikingly different. In these compounds, the transient produced upon 355 nm excitation did not react with the electron donors. Instead, this transient reacted rapidly (k > 10(8)-10(9) M-1 s-1) with known electron acceptors, benzyl viologen and ferricyanide. The transient spectrum of the carboxyalkyl-substituted naphthalimides observed immediately after the laser pulse was nearly identical to the one-electron-reduced form of 1,4,5,8-naphthalene diimide (produced independently using the bis-pyridinium-substituted naphthaldiimide). From our studies, we conclude that the transient produced upon nanosecond laser flash photolysis of NDI-(CH2)nCOO- is the species produced upon intramolecular electron transfer from the carboxylate moiety to the singlet excited state of NDI. In separate experiments, we verified that the singlet excited state of NDI-pyr does, indeed, react intermolecularly with acetate, alanine, and glycine. The process is further substantiated using thermodynamic driving force calculations. The results offer new prospects of the efficient photochemical production of reactive carbon-centered radicals.     

New reagents for the facile and sensitive spectrophotometric determination of carbofuran in its formulations and environmental samples

Facile and sensitive spectrophotometric methods were developed for the determination of carbofuran in its formulations and environmental samples by using new reagents. The methods were based on the coupling reaction of hydrolysed product of cabofuran with diazotized reagents, namely, 2,6-dibromo-4-methylaniline, 2,6-dibromo-4-nitroaniline, and 2,4,6-tribromoaniline in basic medium to give color derivatives having the absorption maximum at 468, 474, and 410 nm, respectively. The color derivatives were correspondingly stable for 40, 30, and 16 h. Beer’s law was obeyed in the carbofuran concentration range 0.2–10.0 μg/mL. The proposed methods have been found to be applicable to the determination of carbofuran in its formulations, tap and distilled water, grains, polluted water, plant material (cabbage), and soil samples. The text was submitted by the authors in English.     

Mechanism of 1,4,5,8-naphthalene tetracarboxylic acid dianhydride hydrolysis and formation in aqueous solution

The study of highly conjugated, carbonyl-containing molecules such as 1,4,5,8-naphthalene tetracarboxylic dianhydride, III, is of interest since reactivity differences and transmission of electronic effects through the conjugated framework can be evidenced. The kinetics of hydrolysis of III in aqueous solution were determined from 5 M acid to pH 10. In basic solution hydrolysis of III yields, sequentially, 1,4,5,8-naphthalene diacid monoanhydride, II, and 1,4,5,8-naphthalene tetracarboxylic acid, I. The second order rate constant for alkaline hydrolysis is 200 fold higher for the first ring opening. The water-catalyzed hydrolysis of III yields a pH-dependent mixture of ionic forms of I and II. The rate constant for water-catalyzed hydrolysis of III is 25 fold higher than that for II. In concentrated acid the rates for reaching equilibrium (I, II and III) increase and III is the major product. The pK(a)s of I (3.24, 5.13 and 6.25) and II (3.05, 5.90) were determined by potentiometric, fluorescence and UV spectroscopy titrations and by quantitative fit of the kinetic and equilibrium data. The apparent, pH-dependent, equilibrium constants, K(EqII), for anhydride formation between I and II were obtained from the UV spectra. The quantitative fit of kinetic and equilibrium data are consistent with the assumption that anhydride formation only proceeds with the fully protonated species for both I and II and permitted the estimation of the equilibrium constants for anhydride formation, K(EqII). The value of K(EqII) (I <==> II) between pH 1 and 6 was ca. 5. Geometry optimization calculations in the gas phase of the reactions of III in alkaline, neutral and acid conditions, at the DFT level of theory, gave electronic distributions that were qualitatively consistent with the experimental results.     

Solvent-Free Synthesis of Core-Functionalised Naphthalene Diimides by Using a Vibratory Ball Mill: Suzuki,Sonogashira and Buchwald–Hartwig Reactions

Solvent-free synthesis by using a vibratory ball mill (VBM) offers the chance to access new chemical reactivity, whilst reducing solvent waste and minimising reaction times. Herein, we report the core functionalisation of N,N’-bis(2-ethylhexyl)-2,6-dibromo-1,4,5,8-naphthalenetetracarboxylic acid (Br₂-NDI) by using Suzuki, Sonogashira and Buchwald–Hartwig coupling reactions. The products of these reactions are important building blocks in many areas of organic electronics including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic photovoltaic cells (OPVCs). The reactions proceed in as little as 1 h, use commercially available palladium sources (frequently Pd(OAc)₂) and are tolerant to air and atmospheric moisture. Furthermore, the real-world potential of this green VBM protocol is demonstrated by the double Suzuki coupling of a monobromo(NDI) residue to a bis(thiophene) pinacol ester. The resulting dimeric NDI species has been demonstrated to behave as an electron acceptor in functioning OPVCs.     

Reactivity changes during polyimide formation

The raactivity changes which occur in diamine monomers during polymide formation were investigated. A series of aromatic diamines were reacted with three aromatic anhydrides (including 1,4,5,8-naphthalene tetracarboxylic dianhydride) under different conditions and the products isolated and identified. There was a great range of reactivity changes depending on the conjugation between the two amino groups of the diamine monomer. For highly conjugated groups, imide formation at one group can prevent any reaction at the other, and hence polymer formation is curtailed.     

New imidazoisoquinoline ladder polymers

In previous studies on poly{(7-oxo-7, 10H-benz[de]imidazo[4′,5′:5,6]-benzimidazo-[2,1-a]isoquinoline-3,4:10,11-tetrayl)-10-carbonyl} it was observed that the polymer exhibits very unusual film-forming properties. The ladder polymer forms supermolecular aggregates in solution which translates to a high degree of interchain packing in the bulk. New ladder imidazoisoquinoline polymers have been prepared in an effort to relate the variance of molecular structure to the aggregation behavior of this class of polymers. The polymers were prepared from the solution polycondensation of 1,4,5,8-naphthalene tetracarboxylic acid or dianhydride with 1,2,5,6-tetraaminonaphthalene, 2,3,7,8-tetraaminophenazine and 2,3,7,8-tetraaminodibenzofuran. It was found that the extent of interchain packing in the bulk is dependent to a large degree on the molecular geometry of the polymer backbone.     

Functionalization of the pyridazin-3(2H)-one ring via palladium-catalysed aminocarbonylation

5-Iodo- and 4,5-dibromo-2-methylpyridazin-3(2H)-ones were aminocarbonylated in the presence of various amines including amino acid methyl esters in a palladium-catalysed reaction. The iodo derivative afforded the corresponding amides with complete conversion and high isolated yields. The dibromo derivative has shown unexpectedly high reactivity in this reaction, resulting in 4,5-dicarboxamides using primary amines as N-nucleophiles. Monoaminocarbonylation has not been observed, i.e., neither 4-bromo-5-carboxamide nor 4-carboxamido-5-bromo derivatives have been formed. However, the use of secondary amines such as piperidine and morpholine resulted in the formations of mixtures of amino-substituted bromopyridazinones. That is, no carbon monoxide insertion took place in these cases. Some mechanistic details of the formation of aminocarbonylation and amination products are also discussed.