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
Reactions with Electrophiles Control Isomerization from η<sup>5</sup>(π)- to η<sup>1</sup>(P)-Coordination of Phosphinyl-Substituted Benzophospholide Ligands
appropriate ligands and [M(CO)4(norbornadiene)], and 10a,b and 13b were isolated from these reactions and characterized by spectroscopic and X-ray diffraction studies. The course of the studied reactions of 7 with electrophiles suggests that the destabilization of the primary quaternization products is controlled by increased weakening of the π-donor power of the ligand with increasing phosphonium character
A zwitterionic phosphanyl-substituted phosphonio-benzo[c]phospholide as bridging ligand towards dinuclear transition metal carbonyls
作者:Dietrich Gudat、Stefan Häp、Martin Nieger
DOI:10.1016/s0022-328x(01)01208-6
日期:2002.2
The zwitterionic 1-triphenylphosphonio-3-diphenylphosphanyl-benzo[c]phospholide (3) reacts with M-2(CO)(10) (M = Mn, Re) to form the dinuclear complexes [M(CO)(4)}(2)(mu-3)1 (7, 8) in which the metal-metal bond is retained and both metals are bound via the two phosphorus lone-pairs. In contrast, reaction of 3 with CP2Mo2(CO)(4) (Mo dropMo) proceeds with the complete cleavage of the metal-metal bond to yield as final product a complex [MoCp(CO)(2)}(2)(mu-3)] (10) in which both phosphorus lone-pairs of 3 co-ordinate to one metal atom, and the second metal atom is attached in a eta(2)(pi)-co-ordination mode to the benzophospholide pi-electron system. All complexes 7, 8. and 10 were characterised by analytic and spectroscopic data and X-ray diffraction studies. The formation of 10 is preceded by that of an intermediate which could likewise be isolated and whose constitution was assigned on the basis of spectroscopic studies as an isomer of 10 which still contains a metal-metal single bond. The behaviour of 3 marks an interesting contrast to that of 2-phosphanyl-phosphinines which react under similar conditions exclusively under co-ordination via the phosphorus lone-pairs. and fail to induce any breakage of metal-metal bonds. The origin for the observed deviations is discussed in terms of the different pi-acceptor properties of the two types of ligands. (C) 2002 Elsevier Science B.V. All rights reserved.
Haep, Stefan; Szarvas, Laszlo; Nieger, Martin, European Journal of Inorganic Chemistry, 2001, # 11, p. 2763 - 2772
作者:Haep, Stefan、Szarvas, Laszlo、Nieger, Martin、Gudat, Dietrich