CAREER: Dispelling Chemical Misconceptions to Discover New Pnictogen-Chalcogen Bonding/Reactivity and Enhance Transfer Student Success

职业：消除化学误解，发现新的磷元素-硫元素键/反应性并提高转学生的成功率

• 批准号: 2236365
• 负责人: Timothy Johnstone
• 金额: $ 77万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2028-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2236365&HistoricalAwards=false
• 关键词: CAREER; Dispelling; Chemical; Misconceptions; Discover

With funding from the Chemical Synthesis Program in the Division of Chemistry, Dr. Timothy Johnstone of the Department of Chemistry at the University of California–Santa Cruz, will explore the synthesis and reactivity of chemical bonds involving heavy elements of the pnictogen family with elements of the halogen family and the role of chemistry misconceptions in the educational outcomes of transfer students. Chemical bonding is the bedrock of the understanding of chemistry. The discovery of new types of bonds opens access to new, often unexpected types of chemical compounds and reactivity. This project will prepare heretofore unknown compounds of the heavy atoms antimony and bismuth with double bonds to oxygen, sulfur, selenium and tellurium. These heretofore unkown bond types may allow reactivity that has historically been accessible only using very expensive metals such as platinum and gold. Such advancements allow the diversify the sorts of chemical platforms that may be accessed and exploited across the chemical sciences - very fundamental. The educational plan of this proposal focuses on understanding whether chemical misconceptions, which play a role in the learning of all chemistry students, differ between students that transfer into a four-year degree program from the community college system (transfer students) and students that enter directly into a four-year degree program (non-transfer students). The differences in chemical misconceptions held by transfer students and non-transfer students will be elucidated with surveys conducted at UC Santa Cruz. The efficacy of active-learning interventions developed to specifically target these misconceptions will then be tested.This project will target the synthesis of compounds featuring unsaturated bonds between heavy pnictogens (antimony and bismuth) and chalcogens (oxygen, sulfur, selenium, and tellurium): pnictine chalcogenides and pnictinidene chalcogenides. Pnictine chalcogenides feature the pnictogen in the 5+ oxidation state and pnictinidene chalcogenides feature the pnictogen in the 3+ oxidation state; each bears a distinct type of unsaturated bond between the pnictogen and the chalcogen. In cases where there is a significant electronegativity difference between these two elements, the unsaturated bond is highly reactive. To prevent premature quenching of this reactivity, sterically bulky groups will be installed on the pnictogen center to kinetically stabilize the target compounds. Once isolated, their reactivity will be systematically explored, with an emphasis on stoichiometric and catalytic small-molecule activation reactions.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.

借助化学合成计划在化学系的资金中，加利福尼亚大学 - 圣克鲁斯分校化学系的蒂莫西·约翰斯通（Timothy Johnstone）博士将探索涉及卤素家族元素的重元素的化学键的综合和反应性，以及卤素家族元素的重型元素，以及在转移学生的教育量中的化学误差的作用。化学键合是对化学理解的基石。新型键的发现可以访问新的，通常是意外的化学化合物和反应性。该项目将准备迄今未知化合物的重原子锑和鞭毛，并具有与氧，硫，硒和泰瑟岛的双键。这些迄今未知的债券类型可能允许反应性在历史上只能使用铂金和黄金等非常昂贵的金属才能访问。这些进步允许多元化的化学平台多样化，这些化学平台可能会在整个化学科学中访问和探索 - 非常基本。该提案的教育计划着重于了解化学误解在学习所有化学学生中发挥作用的化学误解是否在从社区大学系统（转学学生）转移到四年制学位课程的学生中以及直接进入四年制学位课程（非转学学生）的学生。通过在加州大学圣克鲁斯分校进行的调查，将阐明转学学生和非转移学生的化学误解差异。 The efficiency of active-learning interventions developed to specifically target these misconceptions will then be tested.This project will target the synthesis of compounds featuring unsaturated bonds between heavy pnictogens (antimony and bismuth) and chalcogens (oxygen, sulfur, selenium, and tellurium): Pnictine chalcogenides and pnictinidene chalcogenides. pnictine chalcogenide在5+氧化态中具有pnictogen，而pnictinidene chalcogenides在3+氧化状态下具有pnictogen。每个人都有一种不同类型的pnictogen和chalcogen之间的不饱和键。如果这两个元素之间存在明显的电差异，则不饱和键具有高反应性。为了防止这种反应性过早淬灭，将在pnictogen中心安装散装组，以运动稳定靶化合物。一旦孤立，它们的反应性将被系统地探索，重点是化学计量和催化的小分子激活反应。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的。

项目成果

Steric congestion in heavy pnictines alters oxidative halogenation pathways

• DOI: 10.1016/j.poly.2023.116730
• 发表时间: 2023-11-15
• 期刊: POLYHEDRON
• 影响因子: 2.6
• 作者: Wenger，John S.;Getahun，Addis;Johnstone，Timothy C.
• 通讯作者: Johnstone，Timothy C.