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In chemistry phosphines are L-type ligands. They are used as ligands for many metal complexes. Perhaps the most popular phosphine ligand used is triphenylphosphine, a shelf-stable solid that undergoes oxidation in air relatively slowly. Unlike most metal ammine complexes, metal phosphine complexes tend to be lipophilic, displaying good solubility in organic solvents. They also are compatible with metals in multiple oxidation states. Because of these two features, metal phosphine complexes are useful in homogeneous catalysis.〔Hartwig, J. F. Organotransition Metal Chemistry, from Bonding to Catalysis; University Science Books: New York, 2010. ISBN 1-891389-53-X〕 Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl), Grubbs' catalyst, and tetrakis(triphenylphosphine)palladium(0). They are both σ-donors and π-acceptors. Phosphine ligands' π-acidity is due to P-C σ * anti-bonding orbitals. Arylphosphines are much stronger π-acceptors than alkylphosphines, which are poor π-acceptors or possibly π-donors. The phosphine with the strongest π-acidity is trifluorophosphine (PF3); its π-acidity approaches that of the carbonyl ligand. File:Wilkinson's-catalyst-2D.png|Wilkinson's catalyst File:Grubbs Catalyst 1st Generation.svg|First generation Grubbs' catalyst bearing tricyclohexylphosphine ligands File:Tetrakis(triphenylphosphine)palladium(0)-3D-sticks.png|Tetrakis(triphenylphosphine)palladium(0), a homoleptic metal phosphine complex ==Preparation== As L-type ligands, phosphines do not change the overall charge of the metal complex. These complexes may be prepared by addition of phosphines to a coordinatively unsaturated metal precursor, or by ligand displacement of another L-type complex, such as a solvent molecule acting as a ligand. For example, palladium chloride forms infinite chains due to the bridging chloride ligands; when treated with triphenylphosphine, the coordination polymer degrades, yielding monomeric bis(triphenylphosphine)palladium(II) chloride units. :()n + 2n PPh3 → n PdCl2(PPh3)2 The first phosphine complexes were cis- and trans-PtCl2(PEt3)2 reported by Cahours and Gal in 1870.〔C. A. McAuliffe, Ed. "Transition Metal Complexes of Phosphorus, Arsenic, and Antimony Ligands" J. Wiley, 1973. ISBN 0-470-58117-4.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metal phosphine complex」の詳細全文を読む スポンサード リンク
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