树枝状高分子简介树枝状高分子简介2008年9月1从多官能团内核出发，从多官能团内核出发，通过支化基元逐步重复通过支化基元逐步重复生长生长,形成具有高度支化结构的形成具有高度支化结构的树枝状树枝状三维大分子。三维大分子。树形大分子的介绍2 Tomalia 在在1985 1985 年利用发散法首次合成树形聚年利用发散法首次合成树形聚( (酰胺酰胺胺胺) ) 型大分子型大分子 Hawker等人在等人在19891989年利用收敛法合成树形冠醚大分子年利用收敛法合成树形冠醚大分子 Balzani 等等人在人在1992 1992 年首次报道了有机过渡金属树形大分子年首次报道了有机过渡金属树形大分子 Percec 等等人在人在19951995年首次报道了液晶型的树形大分子化合物年首次报道了液晶型的树形大分子化合物树形大分子的发展和研究现状q 目前，二十多类，目前，二十多类，200200多种树形大分子被合成出来多种树形大分子被合成出来3树形大分子的合成方法分散法收敛法核心出发逐步引入单体。代数高，分子量大;易有缺陷，产物与反应物不易分离。构造外围分支，由核心连接。空间位阻，速率慢; 缺陷少，产物与反应物易分离。I. Tomalia. J. Polymer. 1985, 17, 117.C. Hawker, J. Frechet. J. Am. Chem. Soc. 1990, 112, 7638.4C.Dufes, I.F. Uchegbu, A.G. Schatzlein. Adv Drug Deli Rev. 2005, 57, 2177PAMAM(聚酰胺- 胺) )合成过程5中心有核内部有空腔，大量支化单元表面均匀分布可修饰的官能基团体积、形状、功能基以及分子量都可以在分子水平精确控制-单分散性高度支化，具有规整，精致的完美结构,高代数呈球形。纳米级尺寸。良好的溶解性，低的黏度。树形大分子的结构特点和性质6低黏度、高溶解性纳米层、聚合液晶、超分子内部受体封装胶团能量和电子转移分子识别催化剂、传感器氧化还原特性外部受体树形大分子的结构特点和性质7A.M. Caminade. Laboratoire de Chimie de Coordination du CNRS 205, route de Narbonne, 31077 Toulouse cedex 4, FRANCE, 20058树形大分子的应用v 超分子化学的应用v 催化剂方面的应用v 生物医学方面的应用v 光学方面的应用v 其他方面的应用9超分子的应用 主-客体体系V. Balzani, F. Vgtle . C. R. Chimie. 2003, 6, 867Fig. 1. Schematic representation of (a) a conventional fluorescent sensor and (b) a fluorescent sensor with signal amplification. Open rhombi indicate coordination sites and black rhombi indicate metal ions. The curved arrows represent quenching processes. In the case of a dendrimer, the absorbed photon excites a single fluorophore component, i.e. quenched by the metal ion, regardless of its position.10超分子的应用 分子自组装Y. Liu, M. Zhao, D.E. Bergbreiter. J. Am. Chem. Soc. 1997, 119, 8720Fig.2. Schematic illustration of the pH-switchable “On/Off” function of the composite film. The polyamine dendrimer units are covalently attached to the Gantrez polymer network. At high pH the film has a net negative charge that excludes anions but passes cations; at low pH it is positively charged and excludes cations but passes anions; and at intermediate pH, it passes both cations and anions.11催化剂方面的应用v 纳米尺寸，形成纳米微环境v 催化活性中心有可变性v 减少金属催化剂流失v 分子结构可精确控制12Fig. 3. Shape-selective olefin epoxidation using dendrimers with a manganese(iii) porphyrin core as catalystsP. Bhyrappa, J. K. Young, J. S. Moore, K.S. Suslick. J. Mol Catal A. 1996, 113. 109催化剂方面的应用Fig.4. Epoxidation results for the intermolecular mixture of alkenes.The ratios of the epoxides are normalized with respect to corresponding Mn(TPP)+ values. Errors are estimated at (5% relative.13substrate/dendrimera conversion, % turnover no.353 to 1 90 3181760 to 1 92 16193530 to 1 94 331817600 to 1 99 17400Fig.5 A unimolecular reverse micelle that efficiently catalyzes the elimination of tertiary halides. The nonpolar corona (yellow) shields the polar interior (blue) of hydroxyl functionalities, which are able to stabilize the carbocation intermediate.M.E. Piotti, F. Rivera, R. Bond, C.J. Hawker, J. M. J. Frechet. J. Am.Chem. Soc. 1999, 121, 9471催化剂方面的应用Table 1. Effect of Changing the Dendrimer Structure and Concentration on the Yield and Turnover Number for the E1 Elimination Reaction (Reaction performed for 43 h at 70 oCa The molar ratio.14Fig.6 Competitive Hydrogenations of 3-Cyclohexene-1-methanol and CyclohexeneUsing Various Pd Catalysts .Reaction conditions: 3-cyclohexene-1-methano l 0.5 mmol, cyclohexene 0.5 mmol, catalyst 5.0 mol of Pd, toluene 12.5 mL, H2 1 atm, 30 oC.树状大分子封装金属粒子（1）小于4 nm纳米粒子，比表面积大、催化效率高（2）表面基团控制溶解性（3）能很好的稳定纳米粒子，并创造纳米微环境（4）能再生使用M. Ooe, M. Murata, T.Mizugaki, K. Ebitani, K. Kaneda. Nano Lett. 2002, 2, 999催化剂方面的应用15生物医学的应用Fig.7 approaches for design of drug delivery systems.药物载体v内部空腔和结合点可内部空腔和结合点可以携带药物。以携带药物。v高密度表面基团经过高密度表面基团经过修饰，改变水溶性和靶修饰，改变水溶性和靶向作用。向作用。v毒性较低，通过扩散毒性较低，通过扩散和生物降解实现药物释和生物降解实现药物释放。放。v分子设计实现生物相分子设计实现生物相溶性和降解性。溶性和降解性。 R. Duncan, L. Izzo. Advanced Drug Delivery Reviews. 2005, 57, 221516外层用聚乙二醇修饰的聚芳醚类树形单分子胶束，疏水内层和亲水外层，在水溶液中有很强的增溶能力，每个胶束能包容9-10个疏水性消炎痛药物分子，具有明显的缓释作用。Fig. 9. Structure of the G2 dendritic unimolecular micelle.药物载体M. Liu, K. Kono , J.M.J. Frechet. Journal of Controlled Release. 2000, 65, 121Fig. 8. In vitro release pro indomethacin from the G3 dendritic unimolecular micelle.17病毒：它的体积也小,转染效率就相对较低.核酸：容易受到细胞毒素的损害。质粒DNA ：易受到血浆和血清蛋白的降解.脂质体：它有细胞毒性反应。基因载体U. Boas, P.M.H. Heegaard. Chem. Soc. Rew. 2004, 33, 43.D.A. Tomalia. Prog. Polym. Sci. 2005, 30, 294生物医学的应用Fig.10. Top row: Three dimensional depiction of conformational change of an amino-terminated PAMAM dendrimer at increasing pH . Middle row: Two-dimensional depiction of the conformational change of an amino-terminated PAMAM dendrimer upon increasing pH.Fig. 9 The close dimensional size (nm) of selected proteins to respective generations of ammonia core-dendriPAMAM-(NH2)z dendrimer.v与许多重要蛋白质和生物组装分子的大小及形状很匹配。vPAMAM生理条件下为聚阳离子,且有很好的溶解性， 末端胺基很容易与DNA 中的带负电的磷酸基相互作用。v内部有空腔，促进DNA结合的复合物的稳定性。18基因载体J. Dennig, E. Duncan. Reviews in Molecular Biotechnology. 2002, 90, 339.Fig. 11 Model of activated dendrimer-mediated DNA uptake.In the first step of the transfection process, the DNAactivated-dendrimer complex binds to the surface of the cell. The complex is then taken into the cell by endocytosis, and incorporated into the endosome of the cell. From theendosome the DNA is released into the cytosol. A small percentage of the released DNA reaches the nucleus, where it is transcribed into RNA. In the last step the RNA is transported back into the cytosol and then translated into protein. The exact pathway and metabolism of transfectionreagents after release into the cytosol are still unclear.聚阳离子末端基团： DNA相互作用 (紧密结构) 有效键合到真核细胞表面 细胞内吞 缓冲细胞内PH, 确保复合 物稳定 19核磁共振造影剂（MRI）生物医学的应用M. Fischer, F. Vgtle. Angew. Chem. Int. Ed. 1999, 38, 884.v大量表面基团和空腔：可以增加造影剂复合物的数量v完美结构，大分子尺寸：从血液循环排除慢，成像时间长增加成像的灵敏度和清晰度（驰豫时间长）20H. Kobayashi, S. Kawamoto, T. Saga, N. Sato, T. Ishimori, J. Konishi, K. Ono, K. Togashi, M.W. Brechbiel. Bioconjugate Chem. 2001, 12, 587.核磁共振造影剂（MRI）Fig. 12. Flowchart of the protocol for preparing Avidin-G6-(1B4M-Gd)254.Fig. 13 Micro-MR image of SHIN3 cell pellets incubated with 4mol of Av-G6Gd, G6Gd, Gd-DTPA,21S. Shukla, G. Wu, M. Chatterjee, W. Yang, M. Sekido, L.A. Diop, R. Muller, J.J. Sudimack, R.J. Lee, R.F. Barth, W. Tjarks, Bioconjugate Chem. 2003, 14, 158硼中子俘获治疗试剂叶酸修饰的PAMAM分子可以结合250-400 10B，能够靶向肿瘤细胞，10B与低能中子进行核裂变产生能量以及细胞毒素破坏肿瘤细胞.癌症治疗Fig. 14 Schematic presentation of an EDA core 3rd generation PAMAM dendrimer G3-DE (1), Na(CH3)3NB10H8NCO (2), andfolic acid FA(3).22F. Vgtle, S. Gestermann, R. Hesse, H. Schwierz, B. Windisch. Prog. Polym. Sci. 2000, 25, 987.光学方面的应用光开关Fig. 15. The photo-responsive azobenzene dendrimer.23树状大分子在其他方面应用q 分析化学方面q 表面活性剂q 电化学应用q 纳米材料方面q 液晶材料q 信息储存材料24结论和展望 树树形形大大分分子子材材料料的的研研究究已已成成为为合合成成化化学学的的研研究究热热点点。由由于于独独特特的的结结构构和和性性能能，使使其其在在催催化化、超超分分子子化化学学、生生物物医医学学、光光电电子子材材料料等等领领域域得得到到了了广广泛泛的的研研究究与与应应用用，被被科科学学家家称称为为“有有机机化化学学新新家家庭庭”、“二二十十一一世世纪纪的的新新材料材料”、“新材料的突破新材料的突破”。 目目前前，树树形形大大分分子子的的研研究究尚尚处处于于探探索索和和积积累累阶阶段段，许许多多性性能能还还属属未未知知。随随着着研研究究和和应应用用的的日日益益深深入入，其其特特殊殊的的结结构构伴伴随随特特异异的的性性能能，这这种种材材料料必必将将在在多多个个领领域域显显示广阔的应用前景。示广阔的应用前景。25参考文献1.I. Tomalia. J. Polymer. 1985, 17, 117.2.C. Hawker, J. Frechet. J. Am. Chem. Soc. 1990, 112, 7638.3.C.Dufes, I.F. Uchegbu, A.G. Schatzlein. Adv Drug Deli Rev. 2005, 57, 21774.V. Balzani, F. Vgtle .C. R. Chimie. 2003, 6, 8675.Y. Liu, M. Zhao, D.E. Bergbreiter. J. Am. Chem. Soc. 1997, 119, 87206.P. Bhyrappa, J. K. Young, J. S. Moore, K.S. Suslick. J. Mol Catal A. 1996, 113. 109 7.M.E. Piotti, F. Rivera, R. Bond, C.J. Hawker, J. M. J. Frechet. J. Am.Chem. Soc. 1999, 121, 9471 8.M. Ooe, M. Murata, T.Mizugaki, K. Ebitani, K. Kaneda. Nano Lett. 2002, 2, 9999.R. Duncan, L. Izzo. Advanced Drug Delivery Reviews. 2005, 57, 221510.M. Liu, K. Kono , J.M.J. Frechet. Journal of Controlled Release. 2000, 65, 12111.U. Boas, P.M.H. Heegaard. Chem. Soc. Rew. 2004, 33, 43.12.D.A. Tomalia. Prog. Polym. Sci. 2005, 30, 29413.J. Dennig, E. Duncan. Reviews in Molecular Biotechnology. 2002, 90, 339.14.M. Fischer, F. Vgtle. Angew. Chem. Int. Ed. 1999, 38, 884.15.H. Kobayashi, S. Kawamoto, T. Saga, N. Sato, T. Ishimori, J. Konishi, K. Ono, K. Togashi, M.W. Brechbiel. Bioconjugate Chem. 2001, 12, 587 1.S. Shukla, G. Wu, M. Chatterjee, W. Yang, M. Sekido, L.A. Diop, R. Muller, J.J. Sudimack, R.J. Lee, R.F. Barth, W. Tjarks, Bioconjugate Chem. 2003, 14, 1583.F. Vgtle, S. Gestermann, R. Hesse, H. Schwierz, B. Windisch. Prog. Polym. Sci. 2000, 25, 98726谢谢大家！谢谢大家！27