苝酰亚胺受体的聚集形态对有机太阳电池中激子过程与电子传输的影响（英文）

末端烷基链分叉位置对苝酰亚胺(PBI)线性二联体的堆积模式具有显著影响,进而影响激子过程与载流子传输.二联体两端烷基链分叉位点紧靠苝酰亚胺能够抑制分子长程有序堆积,形成具有较少能量陷阱的无定形聚集态;而两端烷基链分叉位点远离苝酰亚胺则导致多种聚集结构共存,分子间强π-π相互作用位点成为能量陷阱.结果表明, PBI受体的聚集方式对有机太阳电池的性能产生重要影响,需要尽量减少活性层中的多种聚集结构共存以免引起激子解离受限以及载流子传输迟滞.     

含三苯胺结构的非对称型苝酰亚胺的合成及性能

合成了2种含有三苯胺结构的非对称型苝酰亚胺N-(2-乙基己基)-N'-(4-三苯胺)-3,4,9,10-苝二酰亚胺(PDI-ATPA)和4,4',4″-三[N-(2-乙基己基)-3,4,9,10-苝二酰亚胺]-三苯胺(PDI-TATPA).利用核磁共振谱(NMR)、红外光谱(IR)和元素分析等方法表征了2种分子的结构,采用紫外-可见(UV-Vis)吸收光谱和荧光光谱研究了其分子光物理性能及在溶液中的聚集行为,并且对分子轨道、能级和偶极矩进行了分子模拟.研究结果表明,具有星形空间对称结构的苝酰亚胺分子PDI-TATPA在溶液中具有自组装行为;引入的三苯胺结构与苝核形成电子给体-受体结构,发生分子内电子转移(PET),进而导致荧光猝灭.     

一类基于苝酰亚胺和亚苯基亚乙炔基交替共轭聚合物的合成与表征

以1,7"bay"位置溴化苝酰亚胺为电子受体、低聚亚苯基亚乙炔基(OPE)为电子给体,通过Sonagashira反应制备了一系列不同OPE含量的具有p-n结构主链全共轭交替聚合物,并对其光物理和电化学性质进行了表征.紫外-可见吸收光谱表明,聚合物具有较宽的光吸收范围(350~900 nm),有利于提高体系的光吸收效率;荧光光谱实验发现,对苝酰亚胺单元进行选择性激发,产生由分子内电荷分离所导致的荧光猝灭现象,为该材料应用于光伏器件提供了理论和实验依据.     

Bay区取代苝二酰亚胺分子构型及聚集调控:邻位甲基位阻效应

设计并合成了2种苝二酰亚胺分子PBI1和PBI2,研究了bay区的苯氧基团邻位甲基取代对分子构型及分子聚集的影响.通过对单晶结构的分析,发现邻位甲基的引入明显影响苝二酰亚胺分子构型,使得4个苯氧基呈中心对称分布.由于甲基的空间位阻效应,有效地减弱了分子间π-π相互作用,从而提高了分子的溶解性与溶液加工成膜性.研究结果表明,在π共轭分子结构中的关键位置引入小的甲基取代基能够显著调控分子的聚集行为,有效减少光电材料分子中非光电活性(增溶性基团)的含量,对光电材料分子的设计合成具有重要的指导意义.     

受体型有机光伏材料苝二酰亚胺*

苝二酰亚胺作为一种典型的n型材料,具有可见光区强吸收、光和热稳定性较高等突出优点,近年来应用到有机光伏达电池中。本文介绍了苝二酰亚胺及其各种衍生物的结构和性质,综述了其用作有机光伏受体材料（包括小分子型苝二酰亚胺材料、含苝二酰亚胺受体单元的给体-受体双功能分子和含苝二酰亚胺受体单元的给体-受体双缆型聚合物材料）的最新研究进展。     

基于吡咯并吡咯二酮核心的苝二酰亚胺类受体分子的合成及光伏性能

苝二酰亚胺类小分子由于其固有的强分子聚集特性,导致活性层形貌难于调控,器件效率相对于近年来报道的受体-给体-受体型稠环小分子受体一直处于劣势.针对这一关键问题,我们设计并合成了三个以吡咯并吡咯二酮为中心核的双臂型和四臂型苝二酰亚胺类小分子受体.其中,c-PDI2和nc-PDI2两个双臂型分子分别将两个苝二酰亚胺臂置于吡咯并吡咯二酮核心骨架的碳取代位和氮取代位;四臂型PDI4是将四个苝二酰亚胺臂置于吡咯并吡咯二酮核心骨架的四个取代位.通过对三个受体小分子的光谱吸收、能级水平、薄膜形貌以及光伏性能的详细研究,发现三个受体小分子都拥有扭曲的分子结构并由此带来无定形薄膜形貌,表明其分子聚集趋势得到了有效的抑制.相对于双臂型受体分子,四臂型PDI4具有更强的光吸收能力和电子传输性能,从而获得了8.45%的最高光电转换效率,是c-PDI2器件效率的2倍和nc-PDI2器件效率的1.5倍.     

苝酰亚胺和大环化合物的超分子组装(英文)

苝酰亚胺及其衍生物是一类具有良好的π…π堆积能力和优良的光电性能的n型半导体材料,通过该类化合物与大环化合物构筑纳米超分子组装体是近年来化学、材料科学和纳米科学等领域备受关注的研究之一。本文主要论述了近年来以共价或非共价的方法将超分子大环化合物引入到苝酰亚胺体系构筑出各种纳米功能超分子组装体的研究进展,可以认为超分子大环化合物与苝酰亚胺的组装不仅可以调节苝酰亚胺的光物理行为,而且还可以赋予超分子组装体很多新颖的物理化学特性,使其在传感材料和光电器件等方面展现出很大的潜在应用价值。这些研究极大地拓展了构筑新颖苝酰亚胺纳米超分子组装体的方法。我们相信本文对于进一步构筑具有特定结构和功能的苝酰亚胺-大环化合物超分子组装体将起到积极的促进作用。     

一种具有长寿命三线态的锌卟啉-苝酰亚胺超分子的光物理过程

通过吡啶基与金属锌卟啉的配位作用, 合成了一种新型卟啉-苝酰亚胺超分子配合(TPPZn-BPHPDI), 通过核磁共振氢谱确认了超分子体系的形成. 采用荧光滴定方法测得锌卟啉与苝酰亚胺配位作用的平衡常数为5.32×10⁴ L/mol. 纳秒瞬态荧光光谱和瞬态吸收光谱显示, 超分子体系内存在着从卟啉三线态向苝酰亚胺三线态的能量传递过程, 产生了寿命长达101 μs的苝酰亚胺三线态分子.     

苝四羧酸铈在TiO_2纳米晶膜上的光电转化性质

报道了Ce3+和Ce4+两种金属离子桥联苝四羧酸在二氧化钛纳米晶电极上自组装膜的制备,并利用紫外可见光谱、红外光谱、光电子能谱等手段对自组装膜进行了表征. 通过同步辐射光电子能谱确定了自组装膜的HOMO能级. 基于自组装膜敏化二氧化钛纳米晶电极的薄层三明治型太阳能电池具有较好的光电转化性质. 在480 nm, 苝四羧酸敏化二氧化钛电极产生了26.9%的入射单色光子-电子转化效率(IPCE), 而由Ce4+离子或Ce3+离子桥联所形成的自组装膜分别产生了55.8%和39.1%的IPCE. 金属离子桥联苝四羧酸自组装膜相当于一种配合物, 其HOMO能级比苝四羧酸自组装膜的高, 这是形成铈离子桥联苝四羧酸后IPCE提高的一个主要原因.     

芳香环状低聚体的制备方法

芳香环状低聚体的合成是应现代航天、航空、电子、机械等高技术领域对先进复合材料的需求而发展起来的研究领域, 其特有的结构和性能决定了芳香环状低聚体的广泛应用前景,该研究在较短时间内得到快速深入的发展.本文按一步合成法、多步合成法和解聚成环法三种不同路线综述了芳香环状低聚体的制备及其研究现状.     

Suppression of Oligomer Formation and Formation of Non‐Toxic Fibrils upon Addition of Mirror‐Image Aβ42 to the Natural l‐Enantiomer

Racemates often have lower solubility than enantiopure compounds, and the mixing of enantiomers can enhance the aggregation propensity of peptides. Amyloid beta (Aβ) 42 is an aggregation‐prone peptide that is believed to play a key role in Alzheimer's disease. Soluble Aβ42 aggregation intermediates (oligomers) have emerged as being particularly neurotoxic. We hypothesized that the addition of mirror‐image d ‐Aβ42 should reduce the concentration of toxic oligomers formed from natural l ‐Aβ42. We synthesized l ‐ and D ‐Aβ42 and found their equimolar mixing to lead to accelerated fibril formation. Confocal microscopy with fluorescently labeled analogues of the enantiomers showed their colocalization in racemic fibrils. Owing to the enhanced fibril formation propensity, racemic Aβ42 was less prone to form soluble oligomers. This resulted in the protection of cells from the toxicity of l ‐Aβ42 at concentrations up to 50 μm . The mixing of Aβ42 enantiomers thus accelerates the formation of non‐toxic fibrils.     

Assemblies of perylene diimide derivatives with melamine into luminescent hydrogels

We report unique and spontaneous formation of hydrogels of perylene derivatives with melamine. The luminescent gel network is formed by H-type aggregation of the perylene core, supramolecularly cross-linked by melamine units. As a result of controlled aggregation in the extended nanofibers, strong exciton fluorescence emission is observed.     

Synthesis,optical properties,and aggregation behavior of a triad system based on perylene and oligo(p-phenylene vinylene) units

A donor-acceptor-donor triad molecule with a perylene bisimide derivative as electron acceptor, and an oligo(p-phenylene vinylene) (OPV) derivative as electron donor was synthesized (OPV-PERY-OPV). The structure of the triad was characterized by (1)H and (13)C NMR spectroscopy, size-exclusion chromatography (SEC), and MALDI-TOF spectrometry. Absorbance spectra and CD spectroscopic measurements of the triad molecule indicated the formation of aggregates in solvents such as toluene, chloroform, and tetrachloroethane, whereas it was present in the molecularly dissolved state in THF. The (1)H NMR spectra of the molecule in chloroform had, unexpectedly, four doublet peaks for the perylene protons, instead of the two doublets that is generally seen in N,N'-substituted perylene molecules. To understand the aggregation behavior and the splitting of the signals in the (1)H NMR spectra, a simple model compound was synthesized, in which the OPV units were replaced by phenyl groups (Ph-PERY-Ph). (1)H NMR spectra in CDCl(3) and tetrachloroethane again had four doublet peaks for the perylene protons, whereas in THF the perylene protons gave only a single peak. NOE and COSY spectroscopy were used to assign the peaks to their corresponding perylene protons. UV/Vis and CD spectroscopic measurements indicated that, similar to the OPV-PERY-OPV triad molecule, the model compound Ph-PERY-Ph was also present in the aggregated form in solvents such as toluene, chloroform, and tetrachloroethane, and in the molecularly dissolved state in THF. IR measurements of the model molecule in the first set of solvents indicated carbamate bond (bond;OCObond;NHbond;)-induced intermolecular hydrogen bonding, whereas in THF, the molecule was mostly present in the free form. CPK models with a dimeric structure, in which two perylene molecules are held together by intermolecular hydrogen bonding with the perylene core shifted slightly with respect to one another, could account for the optical properties and the observation of the four different peaks in the (1)H NMR spectra in polar solvent. Temperature-dependent (1)H NMR spectroscopic, UV/Vis, and CD measurements indicated that the transition from the aggregated to the molecularly dissolved state took place at higher temperatures. The electrochemical studies indicated that OPV-PERY-OPV was both p- and n-dopable, whereas Ph-PERY-Ph was only n-dopable. Cyclic voltammetry measurements of Ph-PERY-Ph in THF had two reduction peaks corresponding to the reduction of the perylene core to the monoanion and dianion, respectively. In dichloromethane, however, an additional reduction peak at lower potential was observed. This new reduction peak might arise from the hydrogen-bonded species.     

The composite material of perylene bisimide dye in MCM-41 and its photophysical and photochemical properties

The mesoporous material MCM-41 was synthesized by a hydrothermal method, and perylene bisimide dye was incorporated into its channels by impregnation. The absorption, FTIR, fluorescence emission, and decay spectra of perylene bisimide dye in CHCl₃ and in MCM-41 were studied to investigate the effect of the one-dimensional channel of MCM-41 on the photophysical and photochemical properties of the dye. The results indicated that the nanochannels of MCM-41 shifted the absorption and emission maxima to red and broadened the spectra, with loss of vibrational structure. The fluorescence decay curves fitted a double-exponential function and the lifetime of perylene bisimide dye in MCM-41 was prolonged. The huge surface area of the mesoporous molecular sieve MCM-41 prevented aggregation of dye molecules, which can thus be used at high concentration.     

双分子膜上染料的吸附性质及对膜结构的影响

系统地研究了染料甲基橙和达旦黄在含席夫碱基囊泡双分子膜阳离子表面上的吸附和聚集，以及由此产生的对膜聚集结构的影响，染料的吸附和聚集可经电子吸收光谱的因吸附产生的沉淀证实，并且ＭＯ的聚集结构的Ｈ－聚集，ＴＹ的聚集结构为Ｊ－聚集。改变ｐＨ的研究表明ＭＯ在变色ｐＨ值以及因形成阳离子而解聚，ＴＹ在酸性条件下亦因离子化程度减弱和部分质子化而使聚集被削弱，但在碱性条件下其聚集产生更大的红移。温度变化的结果显示     

Polyelectrolytes with Main‐Chain Perylene Units

A new soluble polyamine with main chain perylene units is synthesized and subsequently converted into cationic or zwitterionic polyelectrolytes. The optical properties of the monomer 1,6,7,12‐tetrakis(4‐tert‐butylphenoxy)‐3,4,9,10‐tetra(bromomethyl)perylene and the resulting polymers have been studied with special attention to ongoing de/aggregation processes. UV–Vis and PL spectra of the polymers show a distinct concentration and solvent dependency of the optical properties. In contrast to the corresponding monomer complete deaggregation did not occur for the polymers. The environment‐sensitive optical properties should allow applications as sensor materials. The perylene‐containing polyelectrolytes may be applied in orthogonal processing schemes toward multilayer electronic devices.     

Synthesis and thermophysical properties of two new protic long-chain ionic liquids with the oleate anion

This work reports the synthesis of 2-hydroxy ethylammonium oleate and bis(2-hydroxy ethyl)ammonium oleate ionic liquids, which have a long aliphatic chain as well as the study of some of their physical properties, in particular the effect of temperature on their density, speed of sound, viscosity, and refractive index. ¹H and ¹³C NMR spectra were used to characterize the chemical structure of the species in concordance with FT-IR spectra. DOSY NMR spectra were used to determine the self-diffusion coefficients of 2-hydroxy ethylammonium oleate ionic liquid, which were consistent with the formation of a lamellar or micellar liquid crystal phase; due the similar structure, a similar aggregation in the bis(2-hydroxy ethyl)ammonium oleate ionic liquid it is expected.     

Aggregation behavior of novel hyaluronan derivatives—a fluorescence probe study

Aggregation properties of hydrophobized hyaluronan with different molecular weights and degrees of substitution were studied using pyrene and perylene as fluorescence probes. Both probes in contrast to native biopolymer confirmed aggregation of modified hyaluronan. The critical aggregation concentration (cac) was determined by the pyrene I₁/I₃ and perylene fluorescence intensity method. The cac value varied both with the molecular weight and the degree of substitution and was between 0.610 and 0.003 g·L^?1. Pyrene polarity scale confirmed formation of hydrophobic domains.     

Poly(ethylene glycol)--oligolactates with monodisperse hydrophobic blocks: preparation, characterization, and behavior in water

Methoxypoly(ethylene glycol)-b-oligo-L-lactate (mPEG-b-OLA) diblock oligomers with monodisperse OLA blocks were obtained by fractionation of polydisperse block oligomers using preparative HPLC. The fractionated oligomers were composed of an mPEG block with a molecular weight of 350, 550, or 750 and an OLA block with a degree of polymerization of 4, 6, 8, or 10. The diblock oligomers with a low PEG content were fully amorphous, with glass transition temperatures ranging from -60 to -20 degrees C, indicating that the blocks were miscible. Upon heating aqueous dispersions of the block oligomers, cloud points, depending on the PEG/OLA ratio of the block oligomer, were observed at temperatures above 40 degrees C. The monodispersity of the hydrophobic block enabled the amphiphilic molecules to form nanoparticles in water with a hydrodynamic radius of 130-300 nm, at concentrations above the critical aggregation concentration (0.4-1 mg/mL), whereas polydisperse mPEG-b-OLAs gave formation of large aggregates. Static light scattering measurements showed that the nanoparticles have a low density (0.6-25 mg/mL), indicating that the particles are highly hydrated. In agreement herewith, the (1)H NMR spectra of nanoparticles in D2O closely resembled spectra in a good solvent for both blocks (CDCl3). It is therefore suggested that the nanoparticles contain a hydrated core of mPEG-b-OLA block oligomers, stabilized by a thin outer PEG layer. The particles were stable for two weeks, except for the mPEG350 series and mPEG750-b-OLA4, indicating that both the PEG block size and the PEG weight fraction of the oligomers determine their stability. The evident self-emulsifying properties of mPEG-b-oligo-l-lactates with monodisperse hydrophobic blocks as demonstrated in this study, together with their expected biocompatibility and biodegradability, make these systems well suitable for pharmaceutical applications.     

Aggregation Behaviour of Some Reactive Dyes

The absorption spectra of aqueous solutions of monochlorotriazine reactive dyes, C.I. Reactive Red 9 and Reactive Orange 13 were measured in the presence of 5, 10, 25 and 50% (v/v) of ethanol, pyridine and dioxane-water mixtures and in varied concentrations of KCl, NaCl and LiCl. The varying position, intensity and shape of absorption bands are interpreted in terms of aggregation and disaggregation of dyes in solutions. The aggregation behaviour of the reactive dyes in solutions and in the presence of additives is related to their apparent deviations from Beer's law and aggregation numbers (N). The aggregation constant (K.) of the monomer/dimer equilibrium is calculated. Dyes in ethanol-water mixtures record a larger aggregation number and aggregation constant than in the presence of pyridine. Dioxane is classified as anon-polar solvent and hence has a more disaggregating influence. The value of the aggregation number and constant are increased with increasing salt conentration and the order of degree of aggregation is KCl > NaCl > LiCl related to the order of ionic radii of K⁺, Na⁺ and Li⁺ ions.