Collect. Czech. Chem. Commun. 1999, 64, 977-985

Reactivity of Sodium Hexaethyl-2,4-dicarba-nido-hexaborate(1-)

Bernd Wrackmeyera,*, Hans-Jörg Schanza, Wolfgang Miliusa and Catherine McCammonb

a Laboratorium für Anorganische Chemie, Universität Bayreuth, D-95440 Bayreuth, Germany
b Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany


Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.

Keywords: Boranes; Carboranes; Iron; NMR spectroscopy, 11B, 13C; X-Ray difraction; Crystal structure; 57Fe Mössbauer spectroscopy; Sandwich complexes.