International Research Fellowship Program: Changing Ligands, Changing Lone Pair Stereochemical Activity: A Theoretical Study of a Divalent Lead Coordination Polymer

0852893 Poduska该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Poduska与Eluvathingal D博士合作。几十年来，研究人员一直试图了解这种现象？失踪？二价铅和其他重的后过渡元素中的孤对立体化学活性。 由于其敏感性的各种因素，如配体空间和碱性，铅？铅的孤对活性很难预测，因此抑制了解决铅毒性问题的努力，无论是设计特定的生物螯合剂还是从受污染的土壤和水中去除铅。 一个全面的化学孤对活性的理解可以从含铅化合物的研究中发展出来，其中配体特征系统地变化，并仔细监测孤对活性的变化。 二维Pb（II）聚合物，由Nordell等人合成，Cui等人，和Shi等人，提供了一个系统研究的机会：孤对是立体化学活性时，Cl是绑定到铅，但不是当Br或I。 PI和主机采用理论方法，结合高层次的密度泛函理论计算与定性，半经验的扩展休克尔分子轨道计算，以确定孤对位置和组成，并连接孤对（在）活动在这些二维聚合物中看到的铅六卤化物。在这个博士后奖学金，PI还将教化学和科学传播课程在本科院校，新成立的科学教育和研究在喀拉拉邦印度研究所。 此外，她还将与卡纳塔克邦Rajya Vijnana Parishat非政府组织一起参加科学外联活动，在印度科学院出版的教育期刊Resonance上发表文章，并与印度研究人员和教育工作者建立长期的科学和外联合作关系。

0852893PoduskaThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Anne M. Poduska to work with Dr. Eluvathingal D. Jemmis at the Indian Institute of Science in Bangalore, India.For decades, researchers have sought to understand the appearance?and disappearance?of lone pair stereochemical activity in divalent lead and other heavy, post-transition elements. Due to its sensitivity to a variety of factors such as ligand sterics and basicity, the lead?s lone pair activity is difficult to predict, thus inhibiting efforts to solve issues of lead toxicity, whether it involves designing specific biological chelating agents or removing lead from contaminated soil and water. A comprehensive chemical understanding of lone pair activity can evolve from studies of lead-containing compounds in which ligand characteristics are systematically varied and the resulting changes in lone pair activity carefully monitored. A two-dimensional Pb(II) polymer, synthesized by Nordell et al., Cui et al., and Shi et al., presents an opportunity for a systematic study: the lone pair is stereochemically active when Cl is bound to lead, but not when Br or I are. The PI and host are employing a theoretical approach, combining high-level density functional theory calculations with qualitative, semi-empirical extended Hückel molecular orbital calculations, to identify lone pair location and composition, and to connect the lone pair (in)activity in these two-dimensional polymers with that seen in the lead hexahalides. During this post-doctoral fellowship, the PI will also teach chemistry and a science communication course at an undergraduate institution, the newly established Indian Institute of Science Education and Research in Kerala. Moreover, she will participate in science outreach activities with the Karnataka Rajya Vijnana Parishat NGO, publish articles in Resonance, an educational journal produced by the Indian Academy of Sciences, and establish long-term science and outreach collaborations with Indian researchers and educators.