Designing Moisture and Light Stable Group 14 Homo- and Alternating Polymers including Polystannanes

在过去的4年里，我们在Ryerson的研究工作主要集中在制备适合聚合的超配位（5-配位）锡烷单体。温和的金属催化脱氢柔性和非柔性-c，O-和-c，N-配体连接到锡二氢化物导致中等分子量，超配位聚锡烷的分离。这些独特的聚合物在溶液和固体状态下的光稳定性都有显著改善（聚（二丁基）锡烷的光稳定性为90 d，而非10 min）。超配位聚合物还显示出更好的耐湿气性（室温下7天，而聚（二丁基）锡烷为1小时），锡-锡键的接触受到空间拥挤锡中心的几何形状的阻碍。在我们的研究中，我们还发现了通过二烷基和二烷基锡二氢化物与二烷基和二烷基锡二氢化物的室温缩合制备交替聚锡烷的可行途径。这种缩聚途径为制备独特设计的聚锡烷提供了可能性，这些聚锡烷在每个锡原子或其他锡原子上都具有定制的功能。我们对锡化学进步的贡献导致更多的光和湿度稳定的聚锡烷，使得从这些固有导电材料实现可印刷电子产品的最终目标更加接近现实。我们建议在下列具体领域继续目前的这些努力：

Our research efforts at Ryerson over the last 4 years have focussed on the preparation of hypercoordinated (5-coordinate) stannane monomers suitable for polymerization. Mild metal-catalysed dehydrogenation of both flexible and non-flexible -C,O- and -C,N- ligands attached to tin dihydrides has led to the isolation of modest molecular weight, hypercoordinated polystannanes. These unique polymers demonstrate a significant improvement in light stability (> 90 d vs 10 min for poly(dibutyl)stannane) in both the solution and the solid state. The hypercoordinate polymers also display improved resistance to moisture (7 d at ambient vs 1 hr for poly(dibutyl)stannane), with access to tin-tin bonds hindered by the geometry of the sterically crowded tin centres. In our investigations, we have also discovered an accessible route to the preparation of alternating polystannanes via the room-temperature condensation of dialkyl and diaryl tin diamides with dialkyl and diaryl tin dihydrides. This condensation polymerization route has opened the possibilities to the preparation of uniquely designed polystannanes with customized functionality on every tin atom, or every other tin, as required. Our contribution to the advances in tin chemistry leading to more light and moisture stable polystannanes has made the end goal of achieving printable electronics from these intrinsic conducting materials a closer reality. We propose a continuation of these current efforts in the following specific areas: 1) Optimized Light and Moisture Stable High molecular weight film forming Polystannanes: This effort would seek to identify and prepare ligands which enhance overall stability, in particular moisture stability in 5-coordinate polystannanes. Alternating hydrophobic and light absorbing substituents would provide the essential combination of light and moisture stability for polystannanes. 2) Push-Pull Stannanes: Employ condensation chemistry of select tin diamides and tin dihydrides to access a series of intrinsic semi-conducting push-pull polystannanes. The construction of these polystannane materials must ensure facile polymer solubility, stability, and processability in terms of formulation for an inkjet printhead and retain the advantages of an intrinsic push-pull polymer wire. This will be ideally probed by cyclic voltammetry (to show stability) as well as conductivity measurement techniques to support these characteristics. 3) Alternating Group 14 polymers: This involves the condensation between dihydride or diamide stannanes and dihydride and diamide silanes, germanes and plumbanes. A careful match of chemistries is required to identify conditions that promote hybrid polymers of this type. No specific alternating Group 14 polymers are now known. This chemistry opens access to these previously unknown materials.