om011075u_si_002.pdf (349.01 kB)

From the New Arsaalkene ArAsC(Br)SiMe3 to the First Stable Arsaallene, ArAsCCR2 (Ar = 2,4,6-Tri-tert-butylphenyl, CR2 = Fluorenylidene)

Download (349.01 kB)
journal contribution
posted on 21.03.2002 by Mereyim Bouslikhane, Heinz Gornitzka, Henri Ranaivonjatovo, Jean Escudié
The first stable arsaallene, ArAsCCR2 1 (Ar = 2,4,6-tri-tert-butylphenyl, CR2 = fluorenylidene), has been synthesized by a one-pot procedure involving the successive addition of n-butyllithium and fluorenone to the new arsaalkene ArAsC(Br)SiMe3, which presents a Z configuration and a short AsC bond length (1.789(3) Å). An X-ray crystallographic structure determination of air and thermally stable 1 proves its allenic geometry (AsC(1)C(2) bond angle 169.72(19)°, angle between the fluorenylidene plane and the C(15)AsC(1)C(2) mean plane 79.3°) with very short AsC(1) and C(1)C(2) double-bond lengths (1.754(2) and 1.314(3) Å).