Towards moisture and light stable polystannanes

直到最近，对14族元素聚合物的研究在很大程度上还局限于那些含碳的元素。虽然对基于较重的第14族元素、聚硅烷、多锗和聚锡烷的聚合物的独特性质的研究兴趣持续增加，但这些材料的应用已受到相当大的限制。更高的14族聚合物通常对光和湿气都敏感，与传统的聚合物体系相比，它们的制备、分离和使用更加困难。第14族金属的最高聚合物(锡、铅)是一个相对未被开发的研究领域，链状铅聚合物聚铅尚不清楚。较高的14族聚合物的独特性质之一是广泛的离域sigma-sigma键网络，这些网络是由沿主干的元素轨道重叠创建的，使这些产品具有光学和电子方面的兴趣。用锡和铅的均聚物制造高导电性薄膜、一维量子线和可印刷电子产品的潜力还没有被探索过。这项研究将解决这些独特材料以前的合成缺点，并提供第一批湿气和光稳定的聚锡烷的例子。光稳定性将通过引入光稳定侧基(紫外线吸收剂(UVA)、受阻胺光稳定剂(HALS))来实现，以保护主链免受光振荡反应的影响。通过在锡原子上使用体积较大的疏水或环结构来提高对湿气和其他亲核试剂的抵抗力，将提供水分稳定性。上述单体的聚合将通过烷基或芳基锡二氢化合物的脱氢偶联和烷基或芳基二氯化锡的Wurtz偶联和电聚合来完成。金属催化的不饱和碳氢化合物(炔烃或苯炔)插入这些聚合物的主干也将被研究。还将对这些新聚合物进行表征和应用测试。

Until relatively recently, studies of polymers of Group 14 elements have been largely limited to those containing carbon. While research interest into the unique properties of polymers based on heavier Group 14 elements, polysilanes, polygermanes, and polystannanes has continued to increase, applications with these materials has been considerably more limited. Higher Group 14 polymers are in general both light and moisture sensitive, making them more difficult to prepare, isolate and use compared to conventional polymer systems. The highest polymers of Group 14 metals (Sn, Pb) represent a relatively untapped research area with catenated lead polymers, polyplumbanes, still unknown. One of the unique properties of higher Group 14 polymers is the extensive delocalized sigma-sigma bond network created from overlap of elemental orbitals along the backbone, making these products optically and electronically interesting. The potential to make highly conductive films, one-dimensional quantum wires and printable electronics with homopolymers of Sn and Pb have not been explored. This research will address the previous synthetic shortcomings of these unique materials and deliver the first examples of moisture and light stable polystannanes. Light stability will be accomplished by the introduction of light stabilizing side groups (UV absorbers (UVA), hindered amine light stabilizers (HALS)) to protect the backbone from photoscission reactions. Moisture stability will be provided by the use of bulky hydrophobic or ring structures on the tin atom to improve resistance to moisture and other nucleophiles. Polymerization of the above described monomers will be accomplished by dehydrogenative coupling of alkyl or aryl tin dihydrides and Wurtz coupling and electropolymerization of alkyl or aryl tin dichlorides. Metal catalyzed insertion of unsaturated hydrocarbons, (alkynes or benzynes) into the backbone of these polymers will also be investigated. Characterization and applications testing of these new polymers will also be undertaken.