New Early Transition Metal Atom Cluster Materials: In and with Ionic Liquids

新的早期过渡金属原子团簇材料：在离子液体中以及与离子液体一起

• 批准号: 253375057
• 负责人: Professor Dr. Martin Köckerling
• 金额: --
• 依托单位: Festkörperchemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/253375057?language=en
• 关键词: New; Early; Transition; Metal; Atom

Polynuclear transition metal coordination compounds with direct metal-metal bonds, especially hexanuclear, octahedral units of early transition metal atoms (M6-clusters) have attracted scientific and industrial interest for decades already. With the recently started eruption of activities with ionic liquids (ILs) this field seems to be jump-started again, because preliminary experiments indicate, that a multitude of novel compounds is available through the use of ILs in respective chemical reactions. Within the first funding period we succeeded in the synthesis and characterization of a number of new unprecedented hexanuclear niobium cluster compounds using ionic liquids for the preparations. These comprise the first characterized octahedral M6 cluster compounds with intra-chelate ligands. Also, the preparative reaction is the first example of a 6-8 to 6-12 cluster type transformation. Another unprecedented new compound is (BMIm)2[Nb6Cl12(NCS)6{Ag2Cl}]. This contains uncommon [Ag2Cl]+ cations, which form inorganic chelate ligands NCS-Ag-Cl-Ag-SCN, which also connect neighbouring cluster units three-dimensionally. For the synthesis of this compound a diffusion technique was developed, which requires viscous ionic liquids. Using different polar organic solvents is not successful. Using this ionic liquid diffusion technique, a larger number of cluster network compounds was synthesized, which consist of iso-thiocyanato ligated cluster units, which are interconnected through the thiophilic late transition metal cations Ag(I), Cu(I), or Hg(I) or cationic complexes of the same metals. In the research direction of Nb6 cluster compounds with perfluorinated ligands, aiming for weakly coordinating 'cluster ionic liquids', three compounds with trifluoroacetato ligands on the octahedral exo sites were synthesized and characterized. The research in these three fields, WP1: network structures; WP2: chelate ligands; WP3: perfluorinated ligands, is proposed to be continued. The chemistry of the new cluster network structures shall be extended onto EMIm containing ionic liquids, as well as towards attempts to prepare void containing cluster-MOFs. A third extension is directed onto different interconnecting metal ions, i.e. Au(I), Ni(II), Co(II), and Zn(II). Within WP2 a thorough characterization of the cluster compound with intra-cluster 2-aminoethanolato ligands is planned to be done, especially with respect to thermal stability in air. Furthermore, preparative attempts in ionic liquids using o-aminophenolate as ligand are intended. New Nb6 cluster compounds with low melting points and perfluorinated carboxylato ligands are intended to be obtained using hexamethylguanidinium cations instead of tetramethylguanidinium, thereby avoiding hydrogen bonding. Also, further reactions using perfluorinated alcoholato ligands shall be done. In the last working package, WP4, niobium cluster units shall be obtained through electrochemical synthesis in ionic liquids.

具有直接金属-金属键的多核过渡金属配位化合物，特别是早期过渡金属原子的六核、八面体单元(M6-簇合物)，几十年来已经引起了科学和工业的兴趣。随着最近开始的离子液体(ILS)活动的爆发，这个领域似乎再次被启动，因为初步实验表明，通过在各自的化学反应中使用ILS，可以获得许多新的化合物。在第一个资助期内，我们利用离子液体成功地合成和表征了一些新的前所未有的六核Nb簇合物。这些化合物包括第一个具有内螯合配体的八面体M6簇合物。此外，制备反应是6-8至6-12簇型转化的第一个例子。另一种前所未有的新化合物是(BMIm)2[Nb6Cl12(NCS)6{Ag2Cl}]。它含有不常见的[Ag2Cl]+阳离子，形成无机螯合配体NCS-Ag-Cl-Ag-SCN，这些配体也以三维方式连接相邻的簇合物单元。为了合成这种化合物，开发了一种扩散技术，这需要粘性离子液体。使用不同的极性有机溶剂是不成功的。利用这种离子液体扩散技术，合成了大量的团簇网络化合物，这些簇合物由异硫氰酸根连接的团簇单元组成，这些团簇单元通过亲硫的后过渡金属阳离子Ag(I)、Cu(I)或Hg(I)或相同金属的阳离子络合物相互连接。在含全氟配体的Nb6簇合物的研究方向上，针对簇状离子液体配位较弱的特点，合成并表征了三种八面体外位含三氟丙酸配体的化合物。建议继续这三个领域的研究：WP1：网络结构；WP2：螯合配体；WP3：全氟化配体。新的簇状网络结构的化学应扩展到含有离子液体的EMIM，以及制备含有簇状MOF的空穴的尝试。第三个延伸指向不同的互连金属离子，即Au(I)、Ni(II)、Co(II)和Zn(II)。在WP2中，计划对具有簇内2-氨基乙醇酸配体的簇合物进行彻底的表征，特别是关于空气中的热稳定性。此外，还打算在离子液体中以邻氨基苯酚为配体进行制备。新的低熔点的Nb6簇合物和全氟化的羧基配体的目的是用六甲基胍阳离子代替四甲基胍阳离子，从而避免氢键。此外，还应使用全氟化醇配体进行进一步的反应。在最后一个工作包WP4中，将在离子液体中通过电化学合成获得Nb团簇单元。