New ligand technology for solving challenging environmental problems

拟议的研究计划的长期主题是发展化学转化，这将导致更节能和负担得起的工业过程的发展。下面概述的目标涉及选择配体设计，以形成新的配合物，重点是解决主要的环境挑战。***金问题：氰化工艺浸出效率高，技术成熟，是低品位金矿提取回收金的主要工艺。大量氰化钠的使用仍然存在争议，并引起了严重的环境问题，然而，目前还没有开发出可以在工业规模上实施的可行的氰化物替代品。直到现在。我们正在开发一种黄金提取工艺，使用一种适用于黄金开采行业的硫基配体系统，我们预计该工艺将(1)完全消除氰化物的使用，并在此过程中(2)比现有的氰化物技术更快、更便宜，(3)更环保、更安全，(4)简单、易于实施。这项研究的关键将是对黄金提取机制的调查，这样我们就可以更好地了解发生的化学反应，从而进一步改进我们的设计，因为我们彻底改变了黄金行业。***塑料问题：全球塑料产量目前每年超过2亿吨，其中绝大多数直接来自化石燃料。传统聚合物，如聚乙烯和聚丙烯（仅它们就占全球塑料产量的1.25亿吨）可以在环境中持续存在100多年，并在垃圾场和海洋中积累。超过35%的聚乙烯（PE）和聚丙烯（PP）生产用于产品包装，在这些应用中，塑料被短期使用，然后被丢弃。生物可降解聚合物的发展，可以模仿聚乙烯的特性，提供了机会，以生产环境友好的替代品，以传统塑料。从大内酯中获得的聚合物是极有前途的PE模拟物。我们正在开发高效的单组分催化剂，用于大环脂肪环酯的开环聚合，并打算开发这项技术，作为化石燃料聚合物的可行替代品。由此产生的聚合物将模仿基于化石燃料的塑料的特性，但将是可生物降解的，并且来自可再生资源。*** **

The long term theme of the proposed research program is to develop chemical transformations which will result in the development of more energy efficient and affordable industrial processes. The goals outlined below involve selected ligand designs for the formation of new complexes with a focus on solving major environmental challenges.***The gold problem: cyanidation is the dominant process for extraction and recovery of gold from low-grade gold ore due to the high leaching efficiency and mature technology of the process. The use of large amounts of sodium cyanide remains controversial and is of great environmental concern, however no viable alternative to cyanide that can be implemented at an industrial scale has been developed. until now. We are developing a gold extraction process using a sulfur-based ligand system applicable to the gold mining industry that we anticipate will (i) completely eliminate use of cyanide and in the process be (ii) faster and cheaper than existing cyanide technology, (iii) be more environmentally friendly and safer and (iv) be simple and easy to implement. Essential to this research will be an investigation into the mechanism of gold extraction so that we can better understand the chemistry taking place and thus further improve on our designs as we revolutionize the gold industry.***The plastic problem: global plastic production is currently exceeding 200 million tonnes per year, the vast majority of which is derived directly from fossil fuels. Conventional polymers such as polyethylene and polypropylene (which alone account for 125 million tonnes of global plastic production) can persist in the environment for over 100 years and accumulate in waste dumps and in oceans. Over 35% of polyethylene (PE) and polypropylene (PP) production goes to product packaging, applications in which the plastics are used on a short term basis and then disposed. The development of biodegradable polymers that can mimic the properties of PE presents the opportunity to produce environmentally friendly alternatives to conventional plastics. Highly promising candidates for PE mimics are polymers obtained from macrolactones. We are developing efficient, single-component catalysts for the ring-opening polymerization of large-ring aliphatic cyclic esters and intend to develop this technology as a viable alternative to polymers derived from fossil fuels. The resulting polymers would mimic the properties of fossil fuel-based plastics but would be biodegradable and be derived from renewable resources.*** *** **