Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Angew Chem Int Ed Engl. 2016 Mar 18;55(13):4345-7. doi: 10.1002/anie.201600296. Epub 2016 Feb 29.
The red-colored tetraborane(4) B4 (hpp)4 (3; hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate) with a rhomboid B4 skeleton stabilized by four N donors, was synthesized by the reaction of the strong hydride abstraction reagent [(acridine)BCl2 ][AlCl4 ] with the electron-rich diborane(4) [HB(hpp)]2 (1). The salt 3[AlCl4 ]3 was structurally characterized and the presence of unpaired electrons proven by EPR measurements. The unprecedented radical tricationic 3 is distinguished by a high positive charge and boron atoms in a low oxidation state (less than two).
红色的四硼烷(4)B4(hpp)4(3; hpp=1,3,4,6,7,8-六氢-2H-嘧啶并[1,2-a]嘧啶)具有由四个 N 供体稳定的菱形 B4 骨架，通过强氢化物抽离试剂[(吖啶)BCl2][AlCl4]与富电子二硼烷(4)[HB(hpp)]2(1)的反应合成得到。盐 3[AlCl4]3的结构被表征，并通过 EPR 测量证明存在未成对电子。前所未有的自由基三阳离子 3的特点是正电荷高，硼原子的氧化态低(小于二)。
