Construction of two-dimensional polymers by an interfacial metal-organic complexation approach

1922年，赫尔曼·施陶丁格（Hermann Staudinger）将聚合物定义为由大量重复单元组成的大分子，这些重复单元彼此共价连接，形成拓扑线性结构。 今天，这些合成聚合物和生物聚合物的分子结构满足了现代技术的需求，几乎涵盖了我们现代生活的各个方面。高分子化学在理解与一维聚合物（1DP）有关的结构问题方面取得了很大进展，这些问题涉及分子量和重量分布的控制以及端基的立体化学和性质。然而，这些概念还不能应用于合成具有更高维度的大分子，如石墨烯（2DP）或金刚石（3DP）。本研究的目标是通过合理的有机合成方法，得到合适的单体单元，通过界面聚合反应合成单分子金属配位片。单体将基于携带侧联吡啶（bpy）配体的形状持久单元，以便通过正方形平面金属络合将它们彼此连接。虽然对于弱结合的金属离子，这些片不能被认为是共价的，但是对于更强结合的金属离子如Ni 2+和Pt 2+，它们可以达到与完全共价结合的片相当的机械稳定性。此外，获得对这些二维聚合物的内部有序和机械性质的基本洞察是非常有趣的，这将通过许多技术包括AFM，STM，SEM，TEM，GISAXS，拉曼等进行研究，为这些创新材料的未来应用铺平道路。

In 1922, Hermann Staudinger introduced the definition of polymers as macromolecules consisting of a high number of repeat units that are covalently linked to one another forming topologically linear structures. Today, the molecular architectures of these synthetic polymers and biopolymers meet the demands of modern technology covering almost every aspect of our modern life. Polymer chemistry has made great progress in understanding structural issues related to one-dimensional polymers (1DPs) regarding the control of molecular weight and weight distribution as well as stereochemistry and nature of end groups. However, these concepts cannot yet be applied for the synthesis of macromolecules with higher dimensionality like graphene (2DP) or diamond (3DP). Thus, very little success has been made so far in the development of synthetic approaches for the construction of 2DPs.The target of the proposed research is to open up passable and robust trails into monomolecular metal-coordination sheets by interfacial polymerization reactions with suitable monomer units obtained by rational organic synthesis. The monomers will be based on shape-persistent units carrying for lateral bipyridine (bpy) ligands so as to connect them to one another by square planar metal complexation. While with weakly binding metal ions these sheets cannot be considered covalent, with more strongly binding metal ions such Ni2+ and Pt2+ they may reach mechanical stabilities comparable to fully covalently bonded sheets. In addition, it is of great interest to gain a basic insight into the internal order and mechanical properties of these two-dimensional polymers, which shall be investigated by a number of techniques including AFM, STM, SEM, TEM, GISAXS, Raman, etc. to pave the way for future applications of these innovative materials.