锎(Cf)的茂金属配合物的合成和表征
作者：小柯机器人 发布时间：2021/11/20 21:14:15
本期文章：《自然》：Online/在线发表
美国洛斯阿拉莫斯国家实验室Yang Ping报道了锎的茂金属配合物的分离与表征。相关论研究成果于2021年11月17日发表在《自然》。
锎（Cf）是目前可获得的重量超过微克的最重元素。Cf同位素由于其稀缺性和放射性危害，给实验带来了严峻挑战。因此，从5f/6d价轨道参与成键的可及性、自旋-轨道耦合在电子结构中的作用以及与其他f元素相比的反应性模式等化学秘密仍然未解开。有机金属分子是阐明周期表的周期性和成键趋势的基础，随着二十一世纪有机金属钍（Th）通过钚（Pu）化学的复兴，以及较小程度上的镅（Am）的复兴，改变了对化学的理解。然而，锎（和其他跨钚元素）的化学自20世纪70年代以来一直处于休眠状态。
该文中，研究人员通过两毫克249Cf合成和表征[Cf(C5Me4H)2Cl2K(OEt2)]n，开启了对空气/水分敏感的Cf化学。该弯曲的茂金属基序，在铀(U)之外的结构上未经验证，包括第一个结晶特征的Cf–C键。分析表明Cf–C键主要是离子键，共价贡献很小。无色、等电子和同构[Dy(C5Me4H)2Cl2K(OEt2)]n中的Cf 5f轨道能量与镝（Dy）4f相比降低，形成橙色Cf化合物，与通常与Cf化合物相关的浅绿色形成对比。
附：英文原文
Title: Isolation and characterization of a californium metallocene
Author: Goodwin, Conrad A. P., Su, Jing, Stevens, Lauren M., White, Frankie D., Anderson, Nickolas H., Auxier, John D., Albrecht-Schnzart, Thomas E., Batista, Enrique R., Briscoe, Sasha F., Cross, Justin N., Evans, William J., Gaiser, Alyssa N., Gaunt, Andrew J., James, Michael R., Janicke, Michael T., Jenkins, Tener F., Jones, Zachary R., Kozimor, Stosh A., Scott, Brian L., Sperling, Joseph. M., Wedal, Justin C., Windorff, Cory J., Yang, Ping, Ziller, Joseph W.
Issue&Volume: 2021-11-17
Abstract: Californium (Cf) is currently the heaviest element accessible above microgram quantities. Cf isotopes impose severe experimental challenges due to their scarcity and radiological hazards. Consequently, chemical secrets ranging from the accessibility of 5f/6d valence orbitals to engage in bonding, the role of spin–orbit coupling in electronic structure, and reactivity patterns compared to other f elements, remain locked. Organometallic molecules were foundational in elucidating periodicity and bonding trends across the periodic table1,2,3, with a twenty-first-century renaissance of organometallic thorium (Th) through plutonium (Pu) chemistry4,5,6,7,8,9,10,11,12, and to a smaller extent americium (Am)13, transforming chemical understanding. Yet, analogous curium (Cm) to Cf chemistry has lain dormant since the 1970s. Here, we revive air-/moisture-sensitive Cf chemistry through the synthesis and characterization of [Cf(C5Me4H)2Cl2K(OEt2)]n from two milligrams of 249Cf. This bent metallocene motif, not previously structurally authenticated beyond uranium (U)14,15, contains the first crystallographically characterized Cf–C bond. Analysis suggests the Cf–C bond is largely ionic with a small covalent contribution. Lowered Cf 5f orbital energy versus dysprosium (Dy) 4f in the colourless, isoelectronic and isostructural [Dy(C5Me4H)2Cl2K(OEt2)]n results in an orange Cf compound, contrasting with the light-green colour typically associated with Cf compounds16,17,18,19,20,21,22.
DOI: 10.1038/s41586-021-04027-8
Source: https://www.nature.com/articles/s41586-021-04027-8
期刊信息
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：42.778
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