酞菁类光电材料研究新进展

酞菁类化合物具有优异的光电响应性能,是光电材料领域最活跃的研究方向之一.评述了酞菁类化合物近几年在不同领域的研究进展,分析总结了酞菁和取代基酞菁的分子结构、晶体形态对光伏材料、薄膜半导体材料、液晶材料、光导材料和电致发光材料等应用性能的影响以及目前存在的问题,最后对酞菁类光电材料的研究和发展前景进行了展望.     

噌啉类化合物的合成研究进展

噌啉类化合物具有抗癌、抗菌、抗病毒、抗炎和镇静作用等多种生物活性.此外,噌啉环还是优良的电子受体.因此,噌啉骨架已经成为新材料和新药研发中的优势骨架,其合成新方法的研究也受到了化学家们的持续关注.近年来,碳氢官能团化策略迅猛发展,大大推动了噌啉类化合物合成新方法的开发.按照不同的合成策略和反应底物进行分类,综述了近年来噌啉类化合物合成研究的最新进展.     

C―H官能化构建硫醚

硫醚作为一类重要的含硫功能分子,广泛存在于天然产物、药物及有机发光材料中。鉴于硫醚类化合物的重要性,近年来化学家们发展了一系列高效构建硫醚的方法。与传统的有机卤化物/有机硼酸与硫醇交叉偶联的合成方法相比,C―H官能化直接构建硫醚的策略因其步骤经济性、原子经济性备受合成化学家们关注,并取得重要进展。本文根据不同过渡金属进行分类,系统阐述了近年来过渡金属催化/参与C―H官能化或无过渡金属催化C―H官能化构建硫醚这一方向研究进展。     

几种酞菁类光敏剂产生单线态氧能力的研究

本文对若干酞菁类化合物光敏产生1O2能力作了评价. 发现金属酞菁化合物的中心原子对敏化能力有很大影响, 敏化能力按以下次序递降: Zn>Mg>Cu>Mn>Co>Fe. 由于酞菁类化合物溶液中存在二聚体与单体间的平衡, 这一平衡随着浓度丶溶剂极性等条件的变化而移动, 所以酞菁类化合物光敏产生1O2 的能力也能随这些条件而变化.     

酞菁钴－高分子双层膜修饰电极对氧的催化电还原

酞菁钴－高分子双层膜修饰电极对氧的催化电还原董国孝，李纪生，庄瑞舫（中国科学院北京化学研究所，北京，１０００８０）（南京大学配位化学研究所）关键词酞菁合钴，双层膜修饰电极，电还原金属酞菁配合物的催化活性和电催化活性已引起化学家们的极大兴趣，它们作为电...     

卟啉类光敏剂在光动力治疗中的应用研究

作为光动力疗法中至关重要的决定性因素,光敏剂的研究受到越来越多的重视.重点综述了多种新型卟啉类化合物、酞菁类化合物和二氢卟吩类化合物的合成及其在光动力治疗中的应用研究.     

氰胺类化合物的合成及其应用研究进展

氰胺类化合物(R1R2NCN)是一种带有氨基和氰基双官能团的重要精细化工原料,广泛应用于医药、农药、化肥、保健产品和材料等领域,受到合成化学家和药物化学家们的广泛关注.近年来对于氰胺合成方法和其反应的研究发展迅速,不断有新的氰胺合成方法和以其为原料合成各种含氮化合物的反应涌现.本文主要综述了近二十年来发展的氰胺合成方法及氰胺在有机合成中的应用,全面介绍氰胺的各种合成方法和反应,归纳总结他们的特点、规律和优劣势,为氰胺的合成方法和反应性的研究提供帮助.     

L-核苷类抗HIV、HBV活性化合物研究进展

抗病毒新试剂的不断涌现,为HIV、HBV感染者的临床治疗提供了有效的方法.在抗病毒试剂中,核苷类化合物占据了十分重要的地位.本文阐述了核苷类化合物抗病毒的作用机理,介绍了L型核苷的发展历史及一些新型具有抗HIV、HBV生物活性的L型核苷类化合物的分类.同时,通过对一些新型具有抗HIV、HBV生物活性的核苷类化合物如BCH、FTC、OddC、d4A、Fd4C等,D型和L型不同对映异构体抗病毒活性及生物毒性的对比发现,L型异构体比其相应的D型异构体具有抗病毒活性更高、生物毒性更低的特点.药物化学家们对此产生了极大的兴趣,进一步开展了新型L型核苷类化合物设计、合成的相关研究,以便筛选出更安全有效的抗病毒试剂.     

钒氧酞菁的合成及其薄膜结构与光电性能的研究

自从60年前^[1]金属酞菁被发现以来,就引起人们的广泛兴趣,其原因主要在于它们在染料颜料、光化学、催化、和成像中的应用. 和许多其它酞菁衍生物一样,钒氧酞菁具有光导和半导体特性,这使得它在光电子学、电子成像、化学传感器、甚至于微电子器件中有潜在的十分光明的应用前景^[2]. 例如, 钒氧酞菁在电子成像体系中已成为有用的感光材料. 近年来,金属酞菁等有机材料的结晶薄膜开始不断地吸引人们的注意力. 人们考察了不同的金属酞菁如: 酞菁铜、酞菁铅、酞菁镍、和酞菁锡 等的光电导和光电压^[3]. 通常酞菁以几种不同的多晶异构体、即以不同的晶体排列结构方式存在. 因此,其光电特性不仅取决于分子中心的金属原子、而且取决于它们的晶体结构. 总之,值得我们研究钒氧酞菁薄膜的光电特性以及它与吸收光谱和薄膜晶体结构的关系.     

电化学合成氨基酸类化合物的研究进展

氨基酸类化合物在现代医药化学研究和药物设计开发方面具有非常重要的作用,一直以来,开发高效的合成方法学来制备这些氨基酸类化合物的研究吸引了化学家们广泛的研究兴趣.另一方面,近些年电化学反应逐渐兴起成为一种绿色可再生的合成手段,是有机合成化学领域的研究热点,其在氨基酸的合成方面的应用也受到了极大的关注.本综述第一次较为系统...     

Spectral and kinetic properties of the radical ions of chloroboron(III) subnaphthalocyanine

Both the radical anion and radical cation of the chloroboron(III) subnaphthalocyanine (SubNc) cone-shaped macrocycle have been photochemically produced and their kinetics and absorption spectra have been characterised. SubNc is more prone to oxidation but less prone to reduction than its higher homologue, the chloroaluminium(III) phthalocyanine (Pc). Given the higher triplet quantum yield of SubNc compared to Pc, SubNc emerges as a very good photosensitiser for triplet-mediated reduction processes. The radical-ion spectra follow the same patterns found for Pcs, namely absorption bands at longer wavelengths than those of the singlet and triplet excited states.     

Structure,stability, and aromaticity of M?SubPc (MB,Al, and Ga): Computational study

A theoretical investigation on the structure, stability, and aromaticity of M‐subphthalocyanine (M? SubPc; M?B, Al, and Ga) was performed at the B3LYP/6‐31+G*//B3LYP/6‐31G* level. The comparison between M? SubPc and the corresponding M? phthalocyanine (M? Pc) was considered. The geometry optimization of the M? SubPc shows that in the Al? SubPc and Ga? SubPc, the steric repulsions among the three azacoupled isoindole moieties increase, as to their macrocycles tend to be far from planarity. The binding energies of Cl? M … aza‐coupled isoindole corrected by the basis set superposition error (BSSE), and the nucleus‐independent chemical shift (NICS) values at the ring center, which are a simple and effective local aromaticity probe, were calculated. The results show that Al? SubPc is less stable than both B? SubPc and Al? Pc for larger steric repulsion, smaller binding energy, and weaker aromaticity. In the same way, Ga? SubPc is less stable than both B? SubPc and Ga? Pc. In addition, the ring expansion reactivity occurring in B? SubPc was confirmed by the global aromaticity mirrored by the electrophilicity index ω values. Therefore, the Al? SubPc and Ga? SubPc remain unknown, while the corresponding compounds Al? Pc and Ga? Pc are known experimentally. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Tuning Optical and Electron Donor Properties by Peripheral Thio–Aryl Substitution of Subphthalocyanine: A New Series of Donor–Acceptor Hybrids for Photoinduced Charge Separation

Subphthalocyanine (SubPc), a unique ring‐reduced member of the common phthalocyanines family, although known for its higher absorptivity, reveals narrow absorption with peak maxima around 570 nm thus limiting its utility in light‐energy‐harvesting applications. In the present study, by peripheral thio–aryl substitution of SubPc macrocycle, the spectral properties have been modulated to extend the absorption and emission well into the visible/near‐IR region. Additionally, for α‐ring‐substituted derivatives, facile oxidation of SubPc was witnessed, thus making these derivatives better electron donors. Next, the preparation of donor–acceptor dyads containing the well‐known electron acceptor C₆₀ connected to the central boron atom of SubPc was accomplished by making use of the 1,3‐dipolar cycloaddition reaction. Control experiments and free‐energy calculations using the redox and spectral data suggested that the observed fluorescence quenching of SubPc in these dyads is due to electron transfer. Accordingly, transient spectral studies performed both in polar and nonpolar solvents conclusively proved electron transfer to be the quenching mechanism in these dyads. The measured rate constants by fitting kinetic data revealed efficient charge separation and charge recombination processes, suggesting that these dyads could be useful materials for the construction of light‐to‐electricity or light‐to‐fuel production devices.     

Trifluoroethoxy‐Coating Improves the Axial Ligand Substitution of Subphthalocyanine

A novel trifluoroethoxy (TFEO)‐coated SubPc ( 1 ) and various axially functionalised derivatives thereof ( 2 ) have been efficiently synthesised. The advantage of the TFEO‐coating on SubPcs compared to conventional fluorine‐coated or uncoated molecules has been clearly demonstrated, as axial derivatisation has been realised in very good yields. Among various SubPcs synthesised, formyl‐SubPc 2 f has been further used as a building block for the synthesis of donor–acceptor SubPc–C₆₀ hybrid 8 , while iodo‐SubPc 2 e has been used for the synthesis of trifluoroethoxy‐coated SubPc–Pc dyads 9 and 10 . All of these compounds are highly soluble in all common organic solvents, which greatly facilitates their purification and characterisation. The SubPcs 2 a – c incorporating oligoethylene glycol moieties are attractive from a biological point of view, while SubPcs 8 – 10 may prove useful for studies of intramolecular electron‐ and energy‐transfer processes.     

Steps to demarcate the effects of chromophore aggregation and planarization in poly(phenyleneethynylene)s. 1. Rotationally interrupted conjugation in the excited states of 1,4-bis(phenylethynyl)benzene.

A series of photophysical measurements and semiempirical calculations were carried out with 1,4-bis(phenylethynyl)benzene in search of evidence on the effects of phenyl group rotation and chromophore aggregation of oligo- and poly(phenyleneethynylene)s. It is suggested that planarization gives rise to relatively modest shifts of ca. 20-30 nm, which preserve the vibronic structure of the monomer and retain a high emission quantum yield. In contrast, it is proposed that aggregation gives rise to larger shifts and loss of vibronic structure.     

Effects of different light irradiations on structure and optical properties of methoxy-substituted tetraphenylporphyrins

UV lamp, filtered halogen lamp (at 425 nm) and Green laser (532 nm) experiments on a series of meso-substituted tetra phenyl porphyrin, TPP, bearing methoxy peripheral groups together with a metal derivate of 3,4 dimethoxy TPP were lead to different protonation and aggregation structures. Properties of irradiated porphyrins were investigated using their absorption and emission spectra in dichloromethane solution. The results show that the optical properties of the TPP derivates depend on light irradiation source, which shows the tuning of the absorption and emission spectra of the TPP derivates. From the dynamic light scattering measurements, the size distribution of samples was estimated about 5–15 nm in solvent after irradiation. Atomic force microscopy images of deposited porphyrins on the glass surface were shown average particle size between 10 and 30 nm. Particularly, self-assembly of the porphyrin derivates was also observed when green laser was used. We suggest that the irradiation source plays an important role in the controlling of size and morphology of products, and we propose a self-organization model to explain the formation of the porphyrin nanostructures.     

Controlling Electronic Events Through Rational Structural Design in Subphthalocyanine–Corrole Dyads: Synthesis,Characterization, and Photophysical Properties

Porphyrinoids are considered perfect candidates for their incorporation into electron donor–acceptor (D–A) arrays due to their remarkable optoelectronic properties and low reorganization energies. For the first time, a series of subphthalocyanine (SubPc) and corrole (Cor) were covalently connected through a short-range linkage. SubPc axial substitution strategies were employed, which allowed the synthesis of the target molecules in decent yields. In this context, a qualitative synthetic approach was performed to reverse the expected direction of the different electronic events. Consequently, in-depth absorption, fluorescence, and electrochemical assays enabled the study of electronic and photophysical properties. Charge separation was observed in cases of electron-donating Cors, whereas a quantitative energy transfer from the Cor to the SubPc was detected in the case of electron accepting Cors.     

Panchromatic Light Harvesting and Stabilizing Charge-Separated States in Corrole–Phthalocyanine Conjugates through Coordinating a Subphthalocyanine

Owing to the electron-donating and -accepting nature of corroles (Corr) and phthalocyanines (Pc), respectively, we designed and developed two novel covalently linked Corr-Pc conjugates. The synthetic route allows the preparation of the target conjugates in satisfying yields. Comprehensive steady-state absorption, fluorescence, and electrochemical assays enabled insights into energy and electron-transfer processes upon photoexcitation. Coordinating a pyridine-appended subphthalocyanine (SubPc) to the Pc of the conjugate sets up the ways and means to realize the first example of an array composed by three different porphyrinoids, which drives a cascade of energy and charge-transfer processes. Importantly, the SubPc assists in stabilizing the charge-separated state, that is, one-electron oxidized Corr and the one electron-reduced Pc, upon photoexcitation by means of a reductive charge transfer to the SubPc. To the best of our knowledge, this is the first case of an intramolecular oxidation of a Corr within electron-donor–acceptor conjugates by means of just photoexcitation. Moreover, the combination of Corr, Pc, and SubPc guarantees panchromatic absorption across the visible range of the solar spectrum, with the SubPc covering the „green gap“ that usually affects porphyrinoids.     

A dendron of subphthalocyanine trefoil

The synthesis of a dendron composed of tetrameric subphthalocyanine (SubPc) is accomplished by substituting the chlorine groups with phenoxy groups at the axial positions of SubPc with SubPc-triol. The present molecular design of the SubPc-triol introduces three phenol groups at the peripheral positions of the SubPc macrocycle as a tritopic template to construct SubPc dendrons. The self-polycondensation of SubPc-triol as a ‘divergent’ synthesis only gave a trace amount of the hyperbranched arrays due to poor solubility of the SubPc-triol. In contrast, a ‘convergent’ synthesis with the terminal SubPc improved the solubility throughout the reaction and a tetrameric SubPc dendron was obtained in moderate isolated yield.     

Phenyl-ring-bearing cationic surfactants: effect of ring location on the micellar structure

A series of isomeric cationic surfactants (S1-S5) bearing a long alkyl chain that carries a 1,4-phenylene unit and a trimethyl ammonium headgroup was synthesized; the location of the phenyl ring within the alkyl tail was varied in an effort to understand its influence on the amphiphilic properties of the surfactants. The cmc's of the surfactants were estimated using ionic conductivity measurements and isothermal calorimetric titrations (ITC); the values obtained by the two methods were found to be in excellent agreement. The ITC measurements provided additional insight into the various thermodynamic parameters associated with the micellization process. Although all five surfactants have exactly the same molecular formula, their micellar properties were seen to vary dramatically depending on the location of the phenyl ring; the cmc was seen to decrease by almost an order of magnitude when the phenyl ring was moved from the tail end (cmc of S1 is 23 mM) to the headgroup region (cmc of S5 is 3 mM). In all cases, the enthalpy of micellization was negative but the entropy of micellization was positive, suggesting that in all of these systems the formation of micelles is both enthalpically and entropically favored. As expected, the decrease in cmc values upon moving the phenyl ring from the tail end to the headgroup region is accompanied by an increase in the thermodynamic driving force (ΔG) for micellization. To understand further the differences in the micellar structure of these surfactants, small-angle neutron scattering (SANS) measurements were carried out; these measurements reveal that the aggregation number of the micelles increases as the cmc decreases. This increase in the aggregation number is also accompanied by an increase in the asphericity of the micellar aggregate and a decrease in the fractional charge. Geometric packing arguments are presented to account for these changes in aggregation behavior as a function of phenyl ring location.