Borenes and boranes: Silylaminoiminoborenes, such as depicted, were isolated after treatment of halogen triels with silylaminofluoroboranes. In addition, novel aryl- and silyl-substituted diaminofluoroboranes were also prepared in order to substantiate this reaction route.Reactions between the halogen triels AlClMe(2), AlBr(3), GaCl(3) and the silylaminofluoroboranes (Me(3)Si)(2)NB(F)NRSiMe(3) (R=SiMe(3), CMe(3)) afforded the silylaminoiminoborenes, which were isolated as the triel adducts, such as Me(3)Si(Cl(3)Ga)NBNRSiMe(3) (6). In order to extent this reaction path to other fluoroboranes, novel aryl- and silyl-substituted diaminofluoroboranes were synthesised. Because almost no open-chain diaminofluoroboranes had been structurally characterised previously, corresponding fluoroboranes containing no silyl groups were crystallised for purposes of comparison. In complex reactions with the arylsilylaminofluoroboranes [(2,6-(iPr)(2)C(6)H(3))(Me(3)Si)NB(F)NR(2), R=iPr, iBu], amine adducts of borenium salts such as [(iPr)(2)NH-->B(Bu)NH-2,6-(iPr)(2)C(6)H(3)](+)AlCl(4) (-) (13) were obtained.