稀土金属杂环戊二烯：合成及反应

金属有机杂环化合物，如金属杂环戊二烯，是许多金属计量或催化有机合成反应中的关键中间体,在金属有机化学和配位化学领域中占有重要的地位。尽管许多种类的金属杂环戊二烯已报道，而稀土金属杂环戊二烯还没有报道。本项目选择具有高挑战性的稀土金属杂环戊二烯为研究目标，将会有力地促进稀土金属有机化学的发展。主要研究内容包括：（1）通过环戊二烯配体上取代基和1,3-丁二烯-1,4-双金属化合物上取代基的调控，建立通用的方法合成从最小离子半径Sc到最大离子半径La的三类稀土金属杂环戊二烯，利用谱学手段和单晶结构解析鉴定其结构；（2）研究其与碳二亚胺及其它不饱和小分子，如醛，酮，CO和CO2的反应，建立在化学计量的反应之上，寻求发展催化的方法，归纳总结稀土金属离子半径和反应性的规律。

Metallacycles, which are considered as reactive intermediates in metal promoted or catalyzed reactions, play an important role in the field of organometallic and coordination chemistry. Metallacyclopentadienes of s-, p- and d-block metals have received considerable attention in organic synthesis and organometallic chemistry. However, rare-earth metallacyclopentadienes remain unexplored. This project will mainly focus on two aspects: 1) Synthesis and structural characterization of three types of rare-earth metallacyclopentadienes over the full size range of group 3 (Sc, Y) and lanthanide metals (from La to Lu) by tuning the steric hindrance of cyclopentadienyl ligands and 1,4-dilithio-1,3-butadienes or related species; 2) The reaction chemistry of rare-earth metallacyclopentadienes towards carbodiimides, aldehydes，ketones，CO and CO2 will be investigated to expect novel reactivity.