Transition Metal - Main Group Multiple Bonding

在化学系化学合成（SYN）项目的支持下，T。加州大学伯克利分校的唐蒂利将研究既包含过渡金属又包含硅的化合物的新结构和反应。预计该领域的发现将提供新的化合物和化学转化，加速硅基材料的新兴应用，包括有机硅聚合物，粘合剂，润滑剂和半导体。一个主要目标是研究一种鲜为人知的化合物，其特征是硅原子只与金属中心键合。这些化合物预计将表现出尚未彻底探索的特性，但有望帮助改进工业过程。此外，该计划通过提供一个促进批判性思维和解决问题技能发展的研究环境，为研究生和本科生的科学事业做好准备。有一个重要的教育推广组成部分，包括与转学生合作，以方便他们进入伯克利计划。学生将参加外展计划，包括接待高中生，并与当地小学合作，通过互动课程教授基本的科学原理。在培养研究生方面有着长期的良好记录，包括培养学生使用具有挑战性的化学品和试剂。在金属和硅之间具有多重键的复合物，如硅烯复合物（LnM= SiRR '），多年来吸引了人们的极大兴趣，因为它们在催化过程中发挥了重要作用，如硅烯转移或硅氢化。该项目的重点将集中在更好地理解与多重键合相关的化学性质的发展上，其三个主要目标旨在（1）扩展形式上具有M=Si双键的金属硅烯络合物的知识基础，（2）探索一类新的化合物-具有M=Si=M核的分子硅化物络合物，以及（3）开发信息丰富的，周期性关系到金属-元素多重键，包括较重的14族元素锗、锡和铅。一个中心目标将是建立原则，管理的形成和转化的分子硅化物，含有金属连接的硅原子。相比之下，固态金属硅化物作为与硅形成和断开键的催化剂具有巨大的技术重要性，如在由元素硅合成有机硅烷的直接方法中。尽管过渡金属硅化物的技术重要性，很少有人知道他们的反应机制，这种知识差距使得它很难设计的过程中，利用硅化物作为合成中间体。分子硅化物应该服从于硅化合物的均匀转化的机理研究和发展。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Professor T. Don Tilley of the University of California, Berkeley will study new structures and reactions of chemical compounds that incorporate both a transition metal and silicon. Discoveries in this area are expected to provide new compounds and chemical transformations that accelerate emerging applications of silicon-based materials, which include silicone polymers, adhesives, lubricants, and semiconductors. A primary objective is the study of a little understood type of chemical compound that features silicon atoms bonded only to metal centers. Such compounds are expected to exhibit properties that have yet to be thoroughly explored, but promise to aid the improvement of industrial processes. In addition, this program prepares graduate and undergraduate students for careers in science by providing a research environment that fosters critical thinking and problem-solving skill development. There is an important educational-outreach component that include work with transfer students to ease their entry into the Berkeley program. Students will participate in outreach programs that include hosting high school students and engaging with local elementary schools to teach basic scientific principles through interactive lessons. There is a long standing strong record of training of research students; this training includes preparing students to work with challenging chemicals and reagents.Complexes that formally possess a multiple bond between a metal and silicon, such as silylene complexes (LnM=SiRR'), have attracted considerable interest over the years, for their assumed or established role in catalytic processes such as silylene-transfer or hydrosilylation. The focus of this project will center on development of a better understanding of chemical properties associated with multiple bonding, with three primary aims designed to (1) expand the knowledge base for metal silylene complexes formally possessing M=Si double bonds, (2) explore a new class of compounds – molecular silicide complexes with M=Si=M cores, and (3) develop informative, periodic relationships to metal-element multiple bonds involving the heavier group 14 elements germanium, tin, and lead. A central objective will be establishing principles that govern formation and transformations of the molecular silicides, containing metal-ligated silicon atoms. For comparison, solid-state metal silicides are of immense technological importance as catalysts that make and break bonds to silicon, as in the direct process for the synthesis of organosilanes from elemental silicon. Despite the technological importance of transition-metal silicides, little is known about their reaction mechanisms and this knowledge gap makes it difficult to design processes that utilize silicides as synthetic intermediates. Molecular silicides should be amenable to mechanistic investigation and development of homogeneous transformations of silicon compounds.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.