Bis(phosphonio)benzo[c]phospholides (isophosphindolides) 1a,b have been found to react with magnesium or alkali metal naphthalenides MC10H8 (M = Li, Na, K) with reduction of one or both of the phosphonio groups. The main products are the mono- or bis(phosphanyl)-substituted heterocycles 2, 3, 6, 7, which have been characterized by in situ NMR studies and in some cases isolated. Subsequent reaction
und mechanistische Untersuchungen Reaktionen der Phosphonio-Benzophospholid-π-Komplexe 3a, b[Cr] mit [M(CO)5(olefin)] oder der σ-Komplexe 2a, b[M] (M = Cr, Mo, W) mit [M(CO)3(aren)] fuhrten zuden ersten binuklearen Komplexen 4a, b[CrM], in denen Phosphonio-Benzophospholide als μ-verbruckende 8e-Donorliganden gegenuber zwei Metallatomen der Gruppe 6 auftreten. Die Konstitution der Produkte wurde durch
1-Triphenylphosphoniobenzo[c]phospholide 2 which is
accessible via NaBH4 reduction of
1,3-bis(triphenylphosphonio)benzophospholide 1 displays an ambident
coordination ability similar to a phosphinine; this is shown by its
reactions with (cyclooctene)Cr(CO)5 and
(naphthalene)Cr(CO)3 which gave
(Ï(P)-2)Cr(CO)5 and
(η5-2)Cr(CO)3, the first Ï-complex of a
10Ï-aromatic phosphorus heterocycle with a d-block metal.