Designer Ligands and Organometallic Complexes for New Reaction Chemistry, Materials and Catalysis

我的研究项目融合了化学合成、催化和聚合，以解决与化学和整个社会相关的有意义的问题，包括基础和应用问题。更具体地说，我的研究的主要目标是制备新的和不寻常的含有金属的分子，这些分子可以催化合成材料、增值化学品、药品和关键的化学中间体。 在接下来的5年里，我的团队将开发可控的方法来制备不是从化石燃料中提取的新材料。其中一种材料，聚乳酸，可以从廉价的可再生资源中获得，并已在各种利基应用中找到了用途，如可吸收缝合线、骨螺钉和缓释药物。尽管许多工作集中在可以合理改变以改变关键聚合物性质(例如，分子量和相对单体取向/插入顺序(立体化学))的可调催化剂系统上，但仍然存在许多挑战，包括对结构-活性关系的深入理解，以及高活性、耐湿体系的合成。这些信息将被用来创造新一代基于廉价主族(如锌、镁、铟)和活性稀土金属(如钪、Y、钚)的改进型催化剂(中性和带正电的(阳离子))。长期目标包括开发用于合成绿色材料的新催化系统，以及促进对主要族金属和稀土金属发生的反应的基础知识。 我们还将合成低配位的后过渡金属络合物，用于各种成键催化过程，如氢化、硅氢化，特别是具有挑战性的极性单体和非极性烯烃的共聚目标。含有极性官能团的聚合物通常表现出增强的表面性能，例如更好的附着力、可染性和印刷性；然而，此类材料的商业生产仅限于对聚合物结构提供有限控制的工艺，从而限制了聚合物的所需特征。还需要能够聚合范围更广的极性单体的催化剂，以及能够在较低浓度的极性单体下工作的更环保的催化剂。因此，我的团队将在先前我的实验室开发的定制设计的有机骨架(钳形配体)的支持下，制备一系列中性和阳离子的后过渡金属(钯、镍和铁)配合物。随着这些物种的认识，将考察它们作为极性单体与非极性烯烃共聚的催化剂的有效性，以期最终创造出具有商业意义的催化剂，用于合成新的功能材料。

My research program merges chemical synthesis, catalysis and polymerization so as to tackle meaningful questions, both fundamental and applied, which are relevant to chemistry and society at large. More specifically, the primary goal of my research is the preparation of new and unusual metal containing molecules that catalyze the synthesis of materials, value-added chemicals, pharmaceuticals and key chemical intermediates. Over the next 5 years, my group will develop controlled methodologies for preparing new materials that are not derived from fossil fuels. One such material, polylactide, can be sourced from inexpensive, renewable resources and has found utility in various niche applications, such as absorbable sutures, bone screws and slow release pharmaceuticals. Although much effort has focused on tunable catalyst systems that can be rationally altered to vary key polymer properties (e.g. molecular weight and relative monomer orientation/order of insertion (stereochemistry)), many challenges, including a deep understanding of structure-activity relationships and the synthesis of highly active, moisture tolerant systems, remain. This information will be used to create new generations of improved catalysts (neutral and positively charged (cationic)) based on inexpensive main group (e.g. zinc, magnesium, indium) and reactive rare earth metals (e.g. scandium, yttrium, lutetium). Long term goals include the development of new catalytic systems for the synthesis of green materials, as well as contributing to the fundamental knowledge of reactions that occur at both main group and rare earth metals. We will also synthesize low-coordinate late transition metal complexes for application in various bond-forming catalytic processes, such as hydrogenation, hydrosilation, and particularly, the challenging goal of copolymerizing polar monomers and nonpolar olefins. Polymers that incorporate polar functional groups generally exhibit enhanced surface properties, such as better adhesion, dyability, and printability; however, commercial production of such materials is limited to processes that provide limited control over polymer structure, and hence, the desirable features of the polymers. There is also a need for catalysts that can polymerize a wider range of polar monomers, and more environmentally friendly catalysts that can operate under lower concentration of the polar monomer. As such, my team will make a series of neutral and cationic late transition metal (palladium, nickel and iron) complexes supported by custom-designed organic frameworks (pincer ligands) previously developed in my laboratory. As these species are realized, their efficacy as catalysts for the copolymerization of polar monomers with nonpolar olefins will be examined, with an eye to ultimately creating commercially relevant catalysts for the synthesis of new functional materials.