Arene coordination to yttrium(III) via carbon-carbon bond formation

Fryzuk, Michael D, Jafarpour, Laleh, Kerton, Francesca M, Love, Jason, Patrick, Brian O and Rettig, Steven J (1997) Arene coordination to yttrium(III) via carbon-carbon bond formation. Journal of the American Chemical Society, 119 (38). 9071 - 9072. ISSN 0002-7863

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Abstract

The synthesis and characterization of a series of yttrium and lanthanide complexes that incorporate the macrocyclic bis(amidophosphine) ligand PhP(CH2SiMe2NSiMe2CH2)2PPh, [P2N2], are described. The starting materials, {[P2N2]M}2(μ-Cl)2, (M = Y, Sm, Ho, Yb, Lu), are prepared by the reaction of syn-Li2(dioxane)[P2N2] with MCl3(THF)3 in toluene. The reactivity of these complexes toward PhLi and other arylating agents is dependent on the size of the M3+ ion. M = Y and Ho undergo C−C bond formation reactions to give biphenyldiide compounds {[P2N2]M}2{μ-η6:η6‘-(C6H5)2} and {[P2N2]Y}2{μ-η6:η6‘-(C6H4-p-Ph)2}. These have been structurally characterized and show the biphenyl dianion bridging two [P2N2]M fragments. These [P2N2]M fragments migrate over the bridging ligand's π-surface on the NMR time scale. M = Yb yields the paramagnetic monophenyl derivative [P2N2]Yb(C6H5), where the Yb center is coordinatively unsaturated and resides in a distorted square-pyramidal environment. M = Lu results in a mixture of “ate” complexes of the formulation “[P2N2]LuPLiCl”, as evidenced by 7Li NMR. However, the biphenyl product {[P2N2]Lu}2{μ-η6:η6‘-(C6H5)2} can be synthesized via a reductive route. The presence of THF was found to be deleterious to the coupling reaction; in this case, the THF adduct [P2N2]Y(C6H4-p-Me)(THF) was isolated and structurally characterized. The mechanism for the C−C bond formation reaction is described based on the isolation of these yttrium and lanthanide complexes.

Item Type: Article
Schools and Departments: School of Life Sciences > Chemistry
Depositing User: EPrints Services
Date Deposited: 06 Feb 2012 18:30
Last Modified: 19 Mar 2013 13:53
URI: http://sro.sussex.ac.uk/id/eprint/16847
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