A Radical Tricationic Rhomboid Tetraborane(4) with Four‐Center, Five‐Electron Bonding. Issue 13 (29th February 2016)

• Record Type: Journal Article
• Authors: Litters, Sebastian; Kaifer, Elisabeth; Himmel, Hans‐Jörg
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 13(2016)
• Page Start: 4345
• Page End: 4347
• Publication Date: 2016-02-29
• Subjects: boron -- hydride abstraction -- multiple-center bonding -- radicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201600296
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The red‐colored tetraborane(4) [B4 (hpp)4 ] 3+. (3 ; hpp=1, 3, 4, 6, 7, 8‐hexahydro‐2 H ‐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 salt3 [AlCl4 ]3 was structurally characterized and the presence of unpaired electrons proven by EPR measurements. The unprecedented radical tricationic3 is distinguished by a high positive charge and boron atoms in a low oxidation state (less than two). Abstract : Share and share alike : Reaction of the doubly base‐stabilized diborane(4) [HB(hpp)]2 with the strong hydride abstraction reagent [(acridine)BCl2 ][AlCl4 ] leads to the unprecedented red‐colored tetraborane(4) [B4 (hpp)4 ] 3+. with a rhomboid B4 skeleton and four‐center, five‐electron bonding.