球壳烯与侧链含有给电子基团聚合物在光诱导下的电荷转移现象

球壳烯与侧链含有给电子基团聚合物在光诱导下的电荷转移现象喻凤银，周锡煌，李福绵（北京大学化学系，北京，１００８７１）关键词球壳烯，Ｃ＿（６０），电荷转移现象，含二甲氨基苯基的苯乙烯共聚物球壳烯是近年来发现的除金刚石、石墨以外碳的第三种同素异构体［１］...     

碳笼烯-60对Ziegler-Nata催化剂催化苯乙烯聚合的影响

碳笼烯 ６０对Ｚｉｅｇｌｅｒ Ｎａｔａ催化剂催化苯乙烯聚合的影响洪瀚周锡煌李福绵（北京大学化学学院北京１００８７１）关键词碳笼烯 ６０（Ｃ６０），Ｚｉｅｇｌｅｒ Ｎａｔａ催化剂，配位聚合，等规聚苯乙烯Ｃ６０独特的球笼形空间结构和电子结构决定了其有许...     

碳笼烯的高分子化──苯乙烯－烯丙基胺共聚物与C_（60）的反应

碳笼烯的高分子化──苯乙烯－烯丙基胺共聚物与Ｃ＿（６０）的反应田慧洁，周锡煌，李福绵（北京大学化学系北京１００８７１）关键词碳笼烯的高分子化，Ｃ＿（６０），苯乙烯－烯两基胺共聚物碳笼烯（ｆｕｌｌｅｒｅｎｅ）是因其具有特殊的功能性质ｍ而颇受青睐的球簇分...     

C_（60）－PNVC光电导功能材料的形态与结构研究

用高分辨~（１３）Ｃ核磁共振技术与扫描电镜法研究了Ｃ_（６０）修饰的聚乙烯咔唑（ＰＮＶＣ）光电导功能材料。结果表明，Ｃ_（６０）与ＰＮＶＣ共混时彼此间存在快速动态电荷转移行为；Ｃ_（６０）含量对化学修饰的ＰＮＶＣ结构影响显著。最后比较了Ｃ_（６０），ＰＮＶＣ及用金属有机化学法制备Ｃ_（６０）－ＰＮＶＣ共聚物的亚微观形态结构差异。     

C60的产生与石墨晶面的关联（Ⅱ）

Ｃ_（６０）的产生与石墨晶面的关联（Ⅱ）谢兆雄，刘朝阳，王春儒，林逢辰，郑兰荪（厦门大学化学系，固体表面物理化学国家重点实验室，厦门，３６１００５）关键词Ｃ_（６０），球烯，激光烧蚀，高序热解石墨，六元环平面Ｃ６０及其它球烯是当今研究的热点，但有关其形...     

锌酞菁掺杂C60在InP电极上的光电性能研究

Ｃ＿（６０）球烯是具有高度对称性的全碳原子簇，它既是电子受体，又是电子给体，表现出特有的光物理与光化学性能￣［１，２］．近十多年来众多的研究者对具有电子给体和电子受体的共轭π电子体系化合物在光照下的行为进行了深入研究￣［３］，认为用它作为有机光电子功能材料具有十分广阔的前景。随着人们对球烯研究的不断深入，尤其是宏观量球烯的合成与分离已日趋完善，以球烯为基础的有机光电材料必将越来越受到重视．金属酞青化合物由于拥有众多π电子的共轭体系，具有良好的光敏、半导体等性能，是较好的有机光电材料￣［４．５］．但在可见光区，其光敏性仍不够强，本文以ＺｎＰｃ掺杂Ｃ＿（６０）探索其光电性能，以期提高其光敏性．同类研究尚未见文献报道．     

C_（60）与含烯丙基胺聚合物加成物的荧光行为

Ｃ_（６０）与含烯丙基胺聚合物加成物的荧光行为田慧洁，陈立桅，姚光庆，金朝霞，李福绵（北京大学化学系北京１００８７１）关键词脂肪胺，Ｃ_（６０），聚烯丙基胺，荧光Ｃ６０是一高度对称的笼状碳簇分子，室温下难以观察到荧光现象［１］，但我们发现它与聚烯丙基胺...     

PVK／C60电荷转移络合物的光谱研究

利用紫外光谱、荧光光谱研究了ＰＶＫ／Ｃ_（６０）~＊（Ｃ_（６０）~＊与Ｃ_（７０）混合物）体系的光谱行为，实验结果表明，ＰＶＫ与Ｃ_（６０）之间存在电荷转移络合作用。紫外光谱结果表明ＰＶＫ／Ｃ_（６０）~＊电荷转移络合物的特征吸收峰在４７４ｎｍ附近，这与理论计算结果相吻合．ＰＶＫ单元与Ｃ_（６０）之间的最佳匹配约为５：１．荧光光谱结果进一步证明了ＰＶＫ与Ｃ_（６０）~＊之间的电荷转移络合作用的存在。     

碳笼烯(C60)在高分子领域中的研究进展

综述了碳笼烯（Ｃ６０）在高分子领域中的研究进展,包括碳笼烯的高分子化、与聚合物形成电荷转移复合物以及作为催化聚合反应的催化剂。     

球烯－C60和C70的纸制模型

球烯－Ｃ_（６０）和Ｃ_（７０）的纸制模型曹玲华，刘育亭（新疆大学化学系８３００４６）球烯－Ｃ６０和Ｃ７０是具有固定组成和特殊结构的碳素多面体原子簇，是继金刚石和石墨之后，新发现的碳的同素异形体［１，２］。由于它特殊的结构和形态，已引起人们高度的重视。...     

Charge‐Transfer Interactions in Tris‐Donor–Tris‐Acceptor Hexaarylbenzene Redox Chromophores

Symmetric‐ and asymmetric hexaarylbenzenes (HABs), each substituted with three electron‐donor triarylamine redox centers and three electron‐acceptor triarylborane redox centers, were synthesized by cobalt‐catalyzed cyclotrimerization, thereby forming compounds with six‐ and four donor–acceptor interactions, respectively. The electrochemical‐ and photophysical properties of these systems were investigated by cyclovoltammetry (CV), as well as by absorption‐ and fluorescence spectroscopy, and compared to a HAB that only contained one neighboring donor–acceptor pair. CV measurements of the asymmetric HAB show three oxidation peaks and three reduction peaks, whose peak‐separation is greatly influenced by the conducting salt, owing to ion‐pairing and shielding effects. Consequently, the peak‐separations cannot be interpreted in terms of the electronic couplings in the generated mixed‐valence species. Transient‐absorption spectra, fluorescence‐solvatochromism, and absorption spectra show that charge‐transfer states from the amine‐ to the boron centers are generated after optical excitation. The electronic donor–acceptor interactions are weak because the charge transfer has to occur predominantly through space. Moreover, the excitation energy of the localized excited charge‐transfer states can be redistributed between the aryl substituents of these multidimensional chromophores within the fluorescence lifetime (about 60 ns). This result was confirmed by steady‐state fluorescence‐anisotropy measurements, which further indicated symmetry‐breaking in the superficially symmetric HAB. Adding fluoride ions causes the boron centers to lose their accepting ability owing to complexation. Consequently, the charge‐transfer character in the donor–acceptor chromophores vanishes, as observed in both the absorption‐ and fluorescence spectra. However, the ability of the boron center as a fluoride sensor is strongly influenced by the moisture content of the solvent, possibly owing to the formation of hydrogen‐bonding interactions between water molecules and the fluoride anions.     

Fluorescence study of fullerene in organic solvents at room temperature

At room temperature, fluorescence spectra for C60 in organic solvents of four typical kinds have been reported, which indicate that intensity of fluorescence and fine structure of fluorescence peaks are dependent on the interaction between C60 and solvent. It is shown that the solvents of effective electron donors could make a comparatively strong interaction with fullerenes due to formation of the charge transfer adduct, which could greatly distort the molecular symmetry, leading to the strong and well-resolved fluorescence. The strong fluorescence spectra for C70 in room temperature solutions are also observed.     

Photoinduced electron transfer between chlorophyll a and gold nanoparticles

Excited-state interactions between chlorophyll a (Chla) and gold nanoparticles have been studied. The emission intensity of Chla is quenched by gold nanoparticles. The dominant process for this quenching has been attributed to the process of photoinduced electron transfer from excited Chla to gold nanoparticles, although because of a small overlap between fluorescence of Chla and absorption of gold nanoparticles, the energy-transfer process cannot be ruled out. Photoinduced electron-transfer mechanism is supported by the electrochemical modulation of fluorescence of Chla. In absence of an applied bias, Chla cast on gold film, as a result of electron transfer, exhibits a very weak fluorescence. However, upon negatively charging the gold nanocore by external bias, an increase in fluorescence intensity is observed. The negatively charged gold nanoparticles create a barrier and suppress the electron-transfer process from excited Chla to gold nanoparticles, resulting in an increase in radiative process. Nanosecond laser flash experiments of Chla in the presence of gold nanoparticles and fullerene (C60) have demonstrated that Au nanoparticles, besides accepting electrons, can also mediate or shuttle electrons to another acceptor. Taking advantage of these properties of gold nanoparticles, a photoelectrochemical cell based on Chla and gold nanoparticles is constructed. A superior performance of this cell compared to that without the gold film is due to the beneficial role of gold nanoparticles in accepting and shuttling the photogenerated electrons in Chla to the collecting electrode, leading to an enhancement in charge separation efficiency.     

含受电子生色基团烯类单体 - 对乙烯氧基甲基苯甲腈的合成及其荧光“结构自猝灭”效应

含受电子生色基团烯类单体 对乙烯氧基甲基苯甲腈的合成及其荧光“结构自猝灭”效应杜福胜李福绵（北京大学化学学院北京１００８７１）关键词对乙烯氧基甲基苯甲腈，吸收光谱，荧光光谱，“结构自猝灭”效应我们曾经报道过一系列含有给电子荧光生色基团的丙烯酰类及马...     

Carbon Nanodots: Supramolecular Electron Donor–Acceptor Hybrids Featuring Perylenediimides

We describe the formation of charge‐transfer complexes that feature electron‐donating carbon nanodots (CND) and electron‐accepting perylenediimides (PDI). The functionalities of PDIs have been selected to complement those of CNDs in terms of electrostatic and π‐stacking interactions based on oppositely charged ionic head groups and extended π‐systems, respectively. Importantly, the contributions from electrostatic interactions were confirmed in reference experiments, in which stronger interactions were found for PDIs that feature positively rather than negatively charged head groups. The electronic interactions between the components in the ground and excited state were characterized in complementary absorption and fluorescence titration assays that suggest charge‐transfer interactions in both states with binding constants on the order of 8×10⁴ M ^?1 (25 L g^?1). Selective excitation of the two components in ultrafast pump probe experiments gave a 210 ps lived charge‐separated state.     

Photoinduced energy and electron transfer in phenylethynyl-bridged zinc porphyrin-oligothienylenevinylene-C60 ensembles

Donor-bridge-acceptor triad (Por-2TV-C(60)) and tetrad molecules ((Por)(2)-2TV-C(60)), which incorporated C(60) and one or two porphyrin molecules that were covalently linked through a phenylethynyl-oligothienylenevinylene bridge, were synthesized. Their photodynamics were investigated by fluorescence measurements, and by femto- and nanosecond laser flash photolysis. First, photoinduced energy transfer from the porphyrin to the C(60) moiety occurred rather than electron transfer, followed by electron transfer from the oligothienylenevinylene to the singlet excited state of the C(60) moiety to produce the radical cation of oligothienylenevinylene and the radical anion of C(60). Then, back-electron transfer occurred to afford the triplet excited state of the oligothienylenevinylene moiety rather than the ground state. Thus, the porphyrin units in (Por)-2TV-C(60) and (Por)(2)-2TV-C(60) acted as efficient photosensitizers for the charge separation between oligothienylenevinylene and C(60).     

Photoinduced charge separation and charge recombination in the [60]fullerene-diphenylbenzothiadiazole-triphenylamine triad: role of diphenylbenzothiadiazole as bridge

Photoinduced electron-transfer processes of the newly synthesized [60]fullerene-diphenylbenzothiadiazole-triphenylamine (C60-PBTDP-TPA) triad in polar and nonpolar solvents have been studied by using time-resolved transient absorption and fluorescence measurements from picosecond to microsecond regions. By fluorescence lifetime measurements in picosecond time regions, excitation of the charge-transfer transition of the PBTDP-TPA moiety in C60-PBTDP-TPA induces energy transfer to the C60 moiety generating 1C60*-PBTDP-TPA, competitively with charge separation generating C60*--PBTDP-TPA*+. From 1C60*-PBTDP-TPA, which is generated directly and indirectly, charge separation occurs generating C60*--PBTDP-TPA*+ in polar solvents. The C60*--PBTDP-TPA*+ formed via the singlet excited states decayed within a few nanoseconds as revealed by the picosecond transient absorption spectra. In the nanosecond time region, C60*--PBTDP-TPA*+ is produced slowly, probably via 3C60*-PBTDP-TPA. Lifetimes of such slowly generated C60*--PBTDP-TPA*+ were longer than 1 micros, which are the longest values among the C60-bridge-TPA triad systems reported hitherto at room temperature. Roles of the PBTDP-TPA moiety with twisted intermolecular charge-transfer character playing as energy donor and electron donor in addition to the bridge have been disclosed.     

Supramolecular carbon nanotube-fullerene donor-acceptor hybrids for photoinduced electron transfer

Photoinduced electron transfer in a self-assembled single-wall carbon nanotube (SWNT)-fullerene(C60) hybrid with SWNT acting as an electron donor and fullerene as an electron acceptor has been successfully demonstrated. Toward this, first, SWNTs were noncovalently functionalized using alkyl ammonium functionalized pyrene (Pyr-NH3+) to form SWNT/Pyr-NH3+ hybrids. The alkyl ammonium entity of SWNT/Pyr-NH3+ hybrids was further utilized to complex with benzo-18-crown-6 functionalized fullerene, crown-C60, via ammonium-crown ether interactions to yield SWNT/Pyr-NH3+/crown-C60 nanohybrids. The nanohybrids were isolated and characterized by TEM, UV-visible-near IR, and electrochemical methods. Free-energy calculations suggested possibility of electron transfer from the carbon nanotube to the singlet excited fullerene in the SWNT/Pyr-NH3+/crown-C60 nanohybrids. Accordingly, steady-state and time-resolved fluorescence studies revealed efficient quenching of the singlet excited-state of C60 in the nanohybrids. Further studies involving nanosecond transient absorption studies confirmed electron transfer to be the quenching mechanism, in which the electron-transfer product, fullerene anion radical, was possible to spectrally characterize. The rates of charge separation, kCS, and charge recombination, kCR, were found to be 3.46 x 10(9) and 1.04 x 10(7) s-1, respectively. The calculated lifetime of the radical ion-pair was found to be over 100 ns, suggesting charge stabilization in the novel supramolecular nanohybrids. The present nanohybrids were further utilized to reduce hexyl-viologen dication (HV2+) and a sacrificial electron donor, 1-benzyl-1,4-dihydronicotinamide, in an electron-pooling experiment, offering additional proof for the occurrence of photoinduced charge-separation and potential utilization of these materials in light-energy harvesting applications.     

Photoinduced charge separation and charge recombination in [60]fullerene-ethylcarbazole and [60]fullerene-triphenylamines in polar solvents

Molecules of C60 covalently connected with N-ethylcarbazole (EtCz) and triphenylamine (TPA) have been synthesized. Photoinduced electron transfer in C60-EtCz and C60-TPA has been studied in polar and nonpolar solvents using time-resolved transient absorption and fluorescence measurements. From the fluorescence lifetimes, the excited singlet state of the C60 moiety (1C60) of C60-TPA generates predominantly C60*--TPA*+, which decays quickly to the ground state within 6 ns even in polar solvents. In the case of C60-EtCz, on the other hand, about half of the 1C60 moiety generates short-lived C60*--EtCz*+, while the other half of the 1C60 moiety is transferred to the 3C60 moiety via intersystem crossing in dimethylformamide, in which the energy level of C60*--EtCz*+ is lower than that of 3C60. Thus, the charge separation takes place via 3C60 generating C60*--EtCz*+, having a lifetime as long as 300 ns, probably because of the triplet spin character of C60*--EtCz*+. A special property of the EtCz moiety to stabilize the hole in the charge-separated state was revealed.