4 Boron
Abstract
Molecular wheels of eight- and nine-atom boron clusters have been observed by photoelectron spectroscopy and their structures confirmed by DFT calculations. The first cationic terminal borylene, containing a FeB double bond, [Cp*Fe(CO)2(Bmesityl)][BArf4] has been synthesised. DFT calculations support a bonding model in which boron engages in π-bonding to both [Cp*Fe(CO)2]+ and mesityl moieties. The first thirteen vertex carborane has been prepared by successive reduction of 1,2-μ-{C6H4(CH2)2}-1,2-closo-C2B10H10 with Na to afford the [7,8-μ-{C6H4(CH2)2}-7,8-nido-C2B10H10]2− ion followed by addition of PhBCl2 to give the unprecedented 13-vertex carborane 1,2-μ-{C6H4(CH2)2}-3-Ph-1,2-C2B11H10 which has a henicosahedral structure.