COMPLEXES OF ELECTROPOSITIVE METALS WITH A HEMILABILE ETHER PHOSPHINE- CRYSTAL-STRUCTURES OF [TICL(4)L], [FEL(2)(O3SCF3)(2)] AND [MO(CO)(3)L(2)] [L=PHCH(2)P(CH(2)CH(2)OET)(2)]

New complexes containing some early transition metals with benzylbis(2 -ethoxyethyl)phosphine (L) have been prepared. Reaction of this potent ially hemilabile terdentate ligand with TICl4 afforded [TiCl(4)L] 1. T he crystal structure shows the metal to have a distorted-octahedral ge ometry, where the ligand acts as a P,O-bonding chelate. Reaction of 1 with AgBF4 and AgO3SCF3 afforded yellow oils which could not be fully characterised, but are tentatively assigned as [TICl(3)L][BF4] and [Ti Cl(3)L][O3SCF3] respectively. The reaction of [Cr(MeCN)(3)(CO)(3)] wit h L resulted in the formation of [Cr(CO)(4)L(2)] 2 in poor yield. This complex can be prepared in high yield by the reaction of [Cr(MeCN)(2) (CO)(4)] with L. The reaction of [M(CO)(3)(C(6)H(3)Me(3)-2,4,6)] (M = Mo or W) with L gave the complex fac-[Mo(CO)(3)L(2)] 3 and [M(CO)(4)L( 2)] (M = Mo 4 or W 5) depending upon reaction conditions. The crystal structure of 3 shows the metal to have a distorted-octahedral geometry , where one 1, bonds as a P,O chelate and the other as a P-donor. P-31 {H-1} NMR spectroscopy indicates this complex to be fluxional in solut ion, where the two ligands readily interchange at high temperatures. T he iron(II) complex [FeL(2)(O3SCF3)(2)] 6 was prepared by the reaction of L and FeCl2 . 4H(2)O with AgO3SCF3. Its crystal structure shows th e metal to have a distorted-octahedral geometry with trans ligands (th rough phosphorus and oxygen) and trans-co-ordinating triflates.