Design, Synthesis and Characterization of Self-Assembling Nanotubes and Nanospheres

该计划的目标是通过预测的自组装获得几个新的具有可控形状、管状和球状的有机簇。我们所针对的管状和球形团簇是通过弱相互作用：氢键和范德沃斯接触结合在一起的。大多数通向管状的亚基具有C3、Ci和S2对称性，要么是由不寻常的氨基酸组成的环肽，要么是顺式构型的聚酰胺。环肽亚基可以堆叠在一起，产生具有非常强的偶极(如α螺旋)或根本没有偶极的导线或管。另一种具有圆盘形状的亚单位可以形成像石墨或T、O或I对称的球这样的片状，比如巴克明斯特富勒烯，可以包裹金属和其他分子物体。这些类型的超分子可直接应用于许多研究和技术领域，如生物传输、药物输送、传感、非线性光学、传导学、光子学、凝胶和其他新材料。该程序基于迭代过程，包括以下所有步骤，最终得到完整的结构性质关系图：步骤1)将仔细设计亚单位，并通过分子模拟研究其自组装。步骤2)亚基的合成将在实验室进行。步骤3)它们的自组装和超分子结构的性质将用几种现代技术，如核磁共振、质谱学、扫描电子显微镜、透射电子显微镜、结晶学等进行研究。步骤4)对结果的分析将导致有用的超分子(可以发表和/或找到应用)或需要微调，在这种情况下，过程将重新开始(步骤1)积累的知识。

The goal of the program is to obtain several new organic clusters having controlled shapes, tubes and spheres, through predicted self-assembly. The tubular and spherical clusters that we are targeting are held together by means of weak interactions: H-bonds and van der Walls contacts. Most sub-units leading to tubes have C3, Ci and S2 symmetry and are either cyclic peptides made from unusual amino-acids or polyamides of cis geometry. The cyclic peptides sub-units can stack on top of each other to generate wires or tubes having either very strong dipoles like alpha helices or no dipole at all. The other type of sub-units having disk shapes can either form sheets like graphite or balls of T, O or I symmetry, like buckminsterfullerene, that could encapsulate metals and other molecular objects. Supermolecules of these types could have direct applications in many areas of research and technology such as biological transport, drug delivery, sensing, non-linear optics, conductivity, photonics, gels and other new materials, catalysis The program is based on an iterative process involving all the following steps to finally get a complete structure properties relationship chart:Step 1) The sub-units will be carefully designed and their self-assembly will be studied by molecular modelling. Step 2) The synthesis of the sub-units will be carried out in the laboratory.Step 3) Their self-assembly and the properties of the supramolecular architectures will be studied with several modern techniques, like NMR, MS, SEM, TEM, crystallography, etc.Step 4) Analysis of the results will either lead to useful supramolecules (that can be published and/or find applications) or necessitate a fine tuning, in which case the process will be restarted (step 1) with accumulated knowledge.