The magnesiation of H2AsSi'Pr-3 yields the tetramer [(THF)MgAsSi'Pr-3](4) (
1) with a central Mg4As4 heterocubane moiety. The reaction of Sn[N(SiMe3)(2
)](2) with triisopropylsilylarsane gives the hexamer [(SnAsSiPr3)-Pr-i](6)
(2) with an inner hexagonal Sn,As, prism. The molecular structures of both
these compounds have been determined. (C) 2000 Elsevier Science B.V. All ri
ghts reserved.