Synthesis and Characterization of Hypervalent OrganotelluriumAnion Species

高价有机碲阴离子的合成与表征

基本信息

批准号：
18550045
负责人：
MINOURA Mao
金额：
$ 2.68万
依托单位：
Kitasato University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550045/
关键词：
tellurium hypervalent compound crystallography main group element ate complex 超分子化学超原子価 NMR

项目摘要

Intensive efforts have been recently directed toward the hypervalent organochalcogen compounds because of the peculiarity of chalcogens to have two accessible higher oxidation states (IV and VI) which can form variety of compounds of potential. However, very little is known for those with valence VI chalcogen compounds and no hexaarylated chalcogen had been described until we recently reported the synthesis of hexaaryltellurium, Ar6Te, as neutral compound comprising Te^<VI>. Moreover, we also reported on the synthesis and characterization of pentaphenyltelluronium, Ph_5Te^+, as the hypervalent onium compound. Although corresponding anion species, Ph_5Te^-, has been reported as an unstable intermediate in the reaction of Ph_4Te with PhLi, isolated hypervalent tellurium ate compounds have been the missing class of compound. Here, we present the first isolation of hypervalent organotellurium anion species, Ph_5Te^-Li^+(DME)_3, and its structure.The synthesis of Ph_5Te^-Li^+(DME)_3 was achieved by the reaction of freshly prepared Ph_4Te with PhLi. After exchange of the solvent from THE to DME of the mixture, Ph_5Te^-Li^+(DME)_3 was obtained as yellow-orange solid. All manipulations were carried out at -78℃. The single crystals were grown from DME at low temperature and X-ray crystallographic analysis was performed at -160℃. The molecular structure indicates that the Ph_5Te^- has square-pyramidal (pseudo octahedral) structure around the tellurium and the Te-C (basal) bond lengths (2. 329-2. 342 A) are longer than the apical Te-C bond length (2. 153Å). The isolated hypervalent anion is relatively stable at -30℃ in the solid state. The reaction of the tellurium anion with CH_3I or SO_2Cl_2 gave corresponding neutral hexavalent organotellurium species, respectively.

最近，人们对高价有机硫属化合物进行了深入的研究，因为硫属元素具有两种可接近的较高氧化态（IV 和 VI），可以形成各种潜在的化合物，但是，人们对 VI 价硫属元素知之甚少。直到我们最近报道了作为包含Te ^ VI 的中性化合物的六芳基碲Ar 6 Te 的合成，并且没有描述过六芳基化硫属元素。此外，我们还报道了该合成。五苯基碲，Ph_5Te^+，作为高价鎓化合物的表征虽然相应的阴离子物种，Ph_5Te^-，已被报道为 Ph_4Te 与 PhLi 反应中的不稳定中间体，但分离的高价碲酸化合物是缺失的一类。在这里，我们展示了第一个分离的高价有机碲阴离子物种 Ph_5Te^-Li^+(DME)_3 及其结构。 Ph_5Te^-Li^+(DME)_3的合成是通过新鲜制备的Ph_4Te与PhLi的反应实现的，将混合物中的溶剂从THF更换为DME后，得到Ph_5Te^-Li^+(DME)_3。所有操作均在-78℃下从DME中进行，并在-160℃下进行X射线晶体分析。 Ph_5Te^- 在碲周围具有方锥体（伪八面体）结构，并且 Te-C（基础）键长 (2. 329-2. 342 A) 比顶端 Te-C 键长 (2. 153Å) 长).分离出的高价阴离子在固态下在-30℃下比较稳定。碲阴离子与CH_3I或的反应。 SO_2Cl_2分别产生相应的中性六价有机碲物质。