Franz Daniel, Szilvási Tibor, Irran Elisabeth, Inoue Shigeyoshi
Institut für Chemie, Anorganische und Analytische Chemie, Technische Universität Berlin, Straße des 17 Juni 135, Sekr. C2, 10623 Berlin, Germany.
Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111 Budapest, Hungary.
Nat Commun. 2015 Nov 27;6:10037. doi: 10.1038/ncomms10037.
Aluminum chalcogenides are mostly encountered in the form of bulk aluminum oxides that are structurally diverse but typically consist of networks with high lattice energy in which the chalcogen atoms bridge the metal centres. This makes their molecular congeners difficult to synthesize because of a pronounced tendency for oligomerization. Here we describe the isolation of the monotopic aluminum chalcogenide (L(Dip)N)AlTe(L(Et))2 (L(Dip)=1,3-(2,6-diisopropylphenyl)-imidazolin-2-imine, L(Et)=1,3-diethyl-4,5-dimethyl-imidazolin-2-ylidene). Unique features of (L(Dip)N)AlTe(L(Et))2 are the terminal position of the tellurium atom, the shortest aluminum-tellurium distance hitherto reported for a molecular complex and the highest bond order reported for an interaction between these elements, to the best of our knowledge. At elevated temperature (L(Dip)N)AlTe(L(Et))2 equilibrates with dimeric {(L(Dip)N)AlTe(L(Et))}2 in which the chalcogen atoms assume their common role as bridges between the metal centres. These findings demonstrate that (L(Dip)N)AlTe(L(Et))2 comprises the elusive Al=Te double bond in the form of an N-heterocyclic carbene-stabilized species.
硫属铝化物大多以块状氧化铝的形式存在，其结构多样，但通常由具有高晶格能的网络组成，其中硫属原子连接金属中心。这使得它们的分子类似物难以合成，因为存在明显的低聚倾向。在此，我们描述了单齿硫属铝化物（L(Dip)N）AlTe(L(Et))₂（L(Dip)=1,3-(2,6-二异丙基苯基)-咪唑啉-2-亚胺，L(Et)=1,3-二乙基-4,5-二甲基-咪唑啉-2-亚基）的分离。据我们所知，（L(Dip)N）AlTe(L(Et))₂的独特之处在于碲原子的末端位置、分子配合物中迄今报道的最短铝-碲距离以及这些元素之间相互作用报道的最高键级。在高温下，（L(Dip)N）AlTe(L(Et))₂与二聚体{(L(Dip)N)AlTe(L(Et))}₂达到平衡，其中硫属原子起到它们在金属中心之间作为桥连原子的常见作用。这些发现表明，（L(Dip)N）AlTe(L(Et))₂以N-杂环卡宾稳定的物种形式包含难以捉摸的Al=Te双键。
