Tuneable, Protected and Processable Polystannanes from a Pincer Platform

来自 Pincer 平台的可调节、受保护和可加工的聚锡烷

• 批准号: RGPIN-2022-03771
• 负责人: Foucher, Daniel
• 金额: $ 2.11万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748533
• 关键词: Tuneable; Protected; Processable; Polystannanes; Pincer

We have recently demonstrated a successful strategy employing hyper-coordinate (5-coordinate) tin centers that have led to the first examples of light and moisture stable tin polymers. This was achieved by incorporating ligands with pendant functionalities that serve as additional 2e- donors; increasing the coordination number at tin and providing a structural shield to nucleophilic attack, moderating the Lewis acidity at the metal and strengthening the sigma-sigma bonds with additional electron density sharing between adjacent tin centers. In several instances, these stable polymers are semi-crystalline and become difficult to process once purified. To enhance the overall design, a pincer ligand architecture with the potential to make three meridional interactions with the tin center and modified with solubilizing groups, is proposed. The 6e- donor nature of this ligand provides ideal structural protection and electron availability to the tin backbone. To prepare polymers, Sn(IV) dihalide (Br, I) intermediates will be accessed from oxidative addition of Sn(II) pincer species, or directly from transmetallation reactions of lithiated pincer ligands with RSnCl3 (R = alkyl, aryl), or alternatively from redistribution reactions of triphenyl containing Sn(IV) pincer small molecules and SnCl4. Density functional theory (DFT) modelling of the small molecule and oligomer pincer species will be used to compare structural fits to X-ray data, probe Sn-Sn bonding, and predict 119Sn NMR chemical resonances. New Pincer containing polystannanes will be prepared from the dehydrogenative coupling of the tin dihydrido species and evaluated. The unique bonding arrangement of pincer containing polystannanes provides numerous access points to tune the band gap of these intrinsic conducting materials, increase film-forming properties and ensure processability via solubilizing long chain alkyl or alkoxy moieties. The performance of these moisture and light stable pincer polystannanes will be evaluated for potential uses as 3D-printable polymeric wires in molecular based electronics.

我们最近展示了一种成功的策略，采用超坐标（5坐标）锡中心，导致光和水分稳定的锡聚合物的第一个例子。这是通过引入具有作为额外的2 e-供体的侧基官能团的配体来实现的;增加锡处的配位数并提供对亲核攻击的结构屏蔽，缓和金属处的刘易斯酸性并通过在相邻锡中心之间共享额外的电子密度来加强σ-σ键。在一些情况下，这些稳定的聚合物是半结晶的，并且一旦纯化就变得难以加工。为了提高整体设计，钳形配体结构的潜力，使三个与锡中心和改性增溶基团的相互作用，提出。该配体的6 e-供体性质为锡骨架提供了理想的结构保护和电子可用性。为了制备聚合物，Sn（IV）二卤化物（Br，I）中间体将从Sn（II）钳形物质的氧化加成获得，或直接从锂化钳形配体与RSnCl 3（R =烷基、芳基）的transmethalide反应获得，或可替代地从含三苯基的Sn（IV）钳形小分子和SnCl 4的再分配反应获得。小分子和低聚物钳形物质的密度泛函理论（DFT）建模将用于比较结构拟合X射线数据，探测Sn-Sn键合，并预测119 Sn NMR化学共振。新的钳含有聚锡烷将制备从双金属锡物种的双金属偶联和评价。含有聚锡烷的钳形物的独特键合布置提供了许多接入点，以调节这些本征导电材料的带隙，增加成膜性能，并通过溶解长链烷基或烷氧基部分来确保可加工性。这些水分和光稳定的钳形聚锡烷的性能将被评估为在分子基电子产品中作为3D可打印聚合物导线的潜在用途。