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)与含受电子生色基团聚合物的电荷转移现象

Ｃ６０与含受电子生色基团聚合物的电荷转移现象邱健姚光庆周锡煌李福绵（北京大学化学与分子工程学院北京１００８７１）关键词Ｃ６０，聚［Ｎ （４ 氰基苯基）丙烯酰胺］，电荷转移现象，荧光光谱随着对球壳烯性质的深入认识，球壳烯与电子给、受体的电荷转移现象日...     

Jahn－Teller畸变后D_（2h） C_（60）~－的电子结构和光谱

用ＩＮＤＯ系列方法对Ｃ_（６０）自由基负离子进行了几何构型优化，得到Ｄ_（２ｈ）对称性的构型，表明Ｃ_（６０）~－确实发生了Ｊａｈｎ－Ｔｅｌｌｅｒ畸变，导致单键变短，双键变长，形成１５种键，９种不等同碳原子，其额外负电荷主要分布在赤道附近。以此构型为基础，计算了Ｃ_（６０）~－的电子光谱，与实验值吻合，在对光谱进行理论指认的同时讨论了光谱红移的原因。     

两种C_（60）－甘氨酸酯衍生物的室温荧光光谱

两种Ｃ_（６０）－甘氨酸酯衍生物的室温荧光光谱周德建，甘良兵，谭海松，骆初平，姚光庆，黄春辉（北京大学稀土材料化学及应用国家重点实验室，北京，１００８７１）关键词Ｃ_（６０）－甘氨酸酯衍生物，浓度猝灭，荧光寿命Ｃ６０在低温或室温及在紫外或可见光的激发下...     

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...     

分子C_(60)CH_2(C_(2V))气相热力学性质的理论研究

自从富勒烯被发现并能常量制备以来,人们就开始了对Ｃ６０衍生物的研究．Ｃ６０ＣＨ２是Ｃ６０最简单的衍生物之一,Ｃ６０ＣＨ２有２种异构体,根据所属点群的对称性划分一种是属Ｃ２Ｖ群的Ｃ６０ＣＨ２（Ｃ２Ｖ）,另一种是属ＣＳ群的Ｃ６０ＣＨ２（ＣＳ）．文献［１］...     

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。     

C_（60）~＋的Jahn－Teller结构畸变

用ＩＮＤＯ系列方法对Ｃ_（６０）的阳离子自由基Ｃ_（６０）~＋进行几何构型优化，得到Ｄ_（５ｄ）对称性的构型，表明Ｃ_（６０）~＋确实发生了Ｊａｈｎ－Ｔｅｌｌｅｒ结构畸变，形成７种键和４种不等同Ｃ原子，且单键变短，双键变长，键长趋于平均化，体系的正电荷和单电子主要分布在赤道附近，从而导致了赤道附近Ｃ原子的高反应活性。     

C_（60）分子间相互作用势及其晶体压缩系数的计算

根据Ｃ（６０）晶体升华焓的实验值求得了Ｃ（６０）分子间相互作用势的解析表达式。用该表达式计算了Ｃ（６０）分别为面心立方和六方晶格时晶体的结合能，讨论了不同晶格的稳定性问题，解释了Ｃ（６０）晶体一般是面心立方的原因。本文还根据Ｃ（６０）分子间相互作用势计算了Ｃ（６０）晶体的压缩系数，并与文献的实验值进行了比较，所得结果与实验值相符合。     

C_（60）化学修饰的PNVC材料的UV－VIS谱研究

本实验采用金属有机化学方法成功地将富勒烯分子引入到ＰＮＶＣ侧链形成ＣＢＰ（ＣｈａｒｍＢｒａｃｅｌｅｔＰｏｌｙｍｅｒ）型共聚功能材料，研究了其ＵＶ－ＶＩｓ谱行为。结果表明，Ｃ_（６０）或Ｃ_（６０）／Ｃ_（７０）混合物化学修饰的产物其紫外可见谱明显向长波方向移动，谱峰范围由２８０ｎｍ扩展至８７０ｎｍ。Ｃ_（６０）含量增加，红移程度增大，在可见区域的吸收程度亦增加。产物主要存在５个特征峰，分别位于２１５ｎｍ、２６５ｎｍ、２９８ｎｍ、３３５ｎｍ、３４５ｎｍ处，其中２１５ｎｍ峰为Ｃ_（６０）仅存的特征峰。最后讨论了不同合成条件与产物硝化处理对其ＵＶ－ＶＩＳ谱行为的影响。     

FULLERENE POLYMERS WITH TUNABLE OPTICAL PROPERTIES

Light transmission spectra of THF solutions of poly (C_(60)-co-methyl methacrylate)s andpoly (C_(60)-co-styrene)s continuously red-shift with increasing concentration. Formation offullerene nanoclusters may be responsible for the unusual spectral shift with concentration.It has long been scientists' dream to "tune" material's properties by simple means, and theC_(60)-containing polymers represent such a group of novel materials whose optical propertiesare predictably and reversibly tunable by a simple change in concentration.     

Precise Synthesis of New Triblock Co- and Terpolymers by a Methodology Combining Living Anionic Polymers with a Specially Designed Linking Reaction

Five A-B-A′, A-C-A′, B-A-B′, C-A-C′, and C-B-C′ triblock terpolymers with block orders difficult to synthesize by sequential polymerization have been successfully synthesized by a new methodology combining living anionic polymers with a specially designed linking reaction using α-phenylacrylate as the reaction site. Here, A(A′), B(B′), and C(C′) represent groups of polymers (having chain-end anions with different nucleophilicities), which are only polymerizable from A(A′) to B(B′) to C(C′) via sequential polymerization. The corresponding polymers are polystyrene (A) and poly(α-methylstyrene) (A′), poly(2-vinylpyridine) (B) and poly(4-vinylpyridine) (B′) and polymers from methacrylate type monomers like poly(methyl methacrylate) (C), poly(tert-butyl methacrylate) (C′), poly(2-hydroxyethyl methacrylate) (C′), poly(2,3-dihydroxypropyl methacrylate) (C′), and poly(ferrocenylmethyl methacrylate) (C′). Furthermore, three synthetically difficult B-A-B, C-A-C, and C-B-C triblock copolymers with molecular asymmetry in both side blocks have also been synthesized by the developed methodology. All of the polymers thus synthesized are quite new triblock terpolymers and copolymers with well-defined structures, i.e., precisely controlled molecular weights, compositions and narrow molecular weight distributions (M_w/M_n ≤ 1.05).     

含水溶性碳笼烯的水凝胶

含水溶性碳笼烯的水凝胶陈立桅郑磊洪瀚李子臣周锡煌李福绵（北京大学化学系北京１００８７１）关键词水溶性碳笼烯，水凝胶，超氧负离子随着碳笼烯（Ｃ６０，Ｃ７０，ｆｕｌｅｒｅｎｅｓ）的简便制取方法［１］的问世，其应用，特别是其材料化自然被提到日程上来．...     

Dextran Hydrogels Containing Poly(N‐isopropylacrylamide) as Grafts and Cross‐Linkers Exhibiting Enzymatic Regulation in a Specific Temperature Range

Summary: Specific temperature‐responsive biodegradable hydrogels were synthesized and characterized in terms of their regulation of enzymatic accessibility based on the physical properties of the temperature‐responsive polymers. The hydrogels consist of glycidyl methacrylate‐modified dextran grafted with the poly(N‐isopropylacrylamide) (PNIPAAm) homopolymer, and cross‐linked by co‐polymerization with NIPAAm and N,N‐dimethylacrylamide (DMAAm). The coil‐globule change in the grafted poly(NIPAAm) chains and only a slight dehydration of the poly(NIPAAm‐co‐DMAAm) cross‐linkers are effective in controlling the enzymatic degradation over a specific temperature range.

The thermo‐responses of the graft chains (steric hindrance) and the crosslinkers (slight deswelling of the hydrogel networks) control the enzymatic degradation of the hydrogel.     

C60与苯乙烯共聚物的制备及光电导性能的研究

通过自由基聚合的方法制备了一系列苯乙烯和Ｃ６０的共聚物。用ＴＧ＆ＤＴＡ,ＧＰＣ和ＤＳＣ等方法对共聚物进行了表征。首次在非共轭结构高分子共聚物体系上获得了光电导信号。光电导研究表明,该类共聚物具有良好光电导性能,并证明光电导来自Ｃ６０本身。     

Synthesis and characterization of side‐chain liquid crystalline ABC triblock copolymers with p‐methoxyazobenzene moieties by atom transfer radical polymerization

A series of novel side‐chain liquid crystalline ABC triblock copolymers composed of poly(ethylene oxide) (PEO), polystyrene (PS), and poly[6‐(4‐methoxy‐4′‐oxy‐azobenzene) hexyl methacrylate] (PMMAZO) were synthesized by atom transfer radical polymerization (ATRP) using CuBr/1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) as a catalyst system. First, the bromine‐terminated diblock copolymer poly(ethylene oxide)‐block‐polystyrene (PEO‐PS‐Br) was prepared by the ATRP of styrene initiated with the macro‐initiator PEO‐Br, which was obtained from the esterification of PEO and 2‐bromo‐2‐methylpropionyl bromide. An azobenzene‐containing block of PMMAZO with different molecular weights was then introduced into the diblock copolymer by a second ATRP to synthesize the novel side‐chain liquid crystalline ABC triblock copolymer poly(ethylene oxide)‐block‐polystyrene‐block‐poly[6‐(4‐methoxy‐4′‐oxy‐azobenzene) hexyl methacrylate] (PEO‐PS‐PMMAZO). These block copolymers were characterized using proton nuclear magnetic resonance (¹H NMR) and gel permeation chromatograph (GPC). Their thermotropic phase behaviors were investigated using differential scanning calorimetry (DSC) and polarized optical microscope (POM). These triblock copolymers exhibited a smectic phase and a nematic phase over a relatively wide temperature range. At the same time, the photoresponsive properties of these triblock copolymers in chloroform solution were preliminarily studied. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4442–4450, 2008     

Photovoltaic performance enhancement using fluorene‐based copolymers containing pyrene units

A set of novel conjugated polyfluorene co‐ polymers, poly[(9,9′‐didecylfluorene‐2,7‐diyl)‐co‐(4,7′‐di‐2‐thienyl‐ 2′,1′,3′‐benzothiadiazole‐5,5‐diyl)‐co‐(pyrene‐1,6‐diyl)], are synthesized via Pd(II)‐mediated polymerization from 2,7‐bis(4′,4′,5′, 5′‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)‐9,9′‐di‐n‐decylfluorene, 4, 7‐di(2‐bromothien‐5‐yl)‐2,1,3‐benzothiadiazole, and 1,6‐dibromopyrene with a variety of monomer molar ratios. The field‐effect carrier mobilities and optical, electrochemical, and photovoltaic properties of the copolymers are systematically investigated. The hole mobilities of the copolymers are found to be in the range 7.0 × 10^?5 ? 8.0 × 10^?4 cm² V^?1 s^?1 and the on/off ratios were 8 × 10³ ? 7 × 10⁴. Conventional polymer solar cells (PSCs) with the configuration ITO/PEDOT:PSS/polymer:PC₇₁BM/LiF/Al are fabricated. Under optimized conditions, the polymers display power conversion efficiencies (PCEs) for the PSCs in the range 1.99–3.37% under AM 1.5 illumination (100 mW cm^?2). Among the four copolymers, P2, containing a 2.5 mol % pyrene component incorporated into poly[9,9′‐didecylfluorene‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PFDTBT) displays a PCE of 3.37% with a short circuit current of 9.15 mA cm^?2, an open circuit voltage of 0.86 V, and a fill factor of 0.43, under AM 1.5 illumination (100 mW cm^?2). © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Photochemical Properties and Activity of Water‐Soluble Polymer/C60 Nanohybrids for Photodynamic Therapy

Water‐soluble star‐like poly(vinyl alcohol)/C₆₀ and poly{[poly(ethylene glycol) acrylate]‐co‐(vinyl acetate)}/C₆₀ nanohybrids are prepared by grafting macroradicals onto C₆₀ and are assessed as photosensitizers for photodynamic therapy. The photophysical and biological properties of both nanohybrids highlight key characteristics influencing their overall efficiency. The macromolecular structure (linear/graft) and nature (presence/absence of hydroxyl groups) of the polymeric arms respectively impact the photodynamic activity and the stealthiness of the nanohybrids. The advantages of both nanohybrids are encountered in a third one, poly[(N‐vinylpyrrolidone)‐co‐(vinyl acetate)]/C₆₀, which has linear grafts without hydroxyl groups, and shows a better photodynamic activity.

     

Synthesis of C60‐containing polyphosphazenes from a new reactive macromolecular intermediate: Polyphophazene azides

A novel synthetic strategy was developed to prepare polyphosphazenes containing C₆₀ moieties as side chains. Thus, a new reactive macromolecular intermediate, polyphosphazene azides ( P1 ), was obtained from poly(dichlorophosphazene) by the direct nucleophilic substitution reaction. Then the azide group in P1 reacted with C₆₀ molecules to afford the first example of C₆₀‐containing polyphosphazenes ( P2 and P3 ). The polymers are soluble in common organic solvents. Molecular structural characterization for the polymers was presented by ¹H NMR, ¹³C NMR, IR, ultraviolet–visible spectra, and gel permeation chromatography. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 194–199, 2004     

The preparation of perfectly alternating poly(amide-imide)s via amide unit containing new diamine

The synthesis of N,N′-bis(4′-amino-4-biphenylene) isophthalamide (BABPI) and its applicability as a new diamine for the preparation of a series of new, high T_g, perfectly alternating poly(amide-imide)s is described. BABPI was synthesized from the catalytic reduction of the corresponding dinitro compound which was prepared by the condensation of isophthaloyl chloride and 4-amino-4′-nitrobiphenyl. The modified selective reduction technique was used for the preparation of 4-amino-4′-nitrobiphenyl from 4,4′-dinitro-biphenyl. Poly(amide-imide)s were synthesized by polycondensation of diamine BABPI with various commercially available aromatic dianhydrides via a conventional two-step procedure. In the first step, poly(amic-acid)s were prepared in a polar aprotic solvent, such as N-methyl pyrrolidone (NMP) at room temperature. Depending on the dianhydride used, intrinsic viscosities of poly(amic-acid)s were found to range between 0.43–0.69 dL/g. Bulk thermal imidization technique was used to obtain fully imidized poly(amide-imide)s at the second step. The synthesized poly(amide-imide)s showed good thermal stability up to 320°C and the 10% weight loss temperatures were recorded in the range of 525–550°C as evidenced by thermogravimetric analysis (TGA). The glass transition temperatures were found to be between 225–235°C from differential scanning calorimeter (DSC) measurements. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1149–1155, 1997