title: Experimental and theoretical study of the regiospecific coordination of RuII and OsII fragments on the lacunary polyoxometalate [alpha-PW11O39]7-.
abstract: New Ru(II) and Os(II) derivatives of the monovacant [alpha-PW(11)O(39)](7-) anion ([PW(11)O(39){M(DMSO)(3)(H(2)O)}](5-) (M = Ru (1), Os (2)) and [PW(11)O(39){Os(eta(6)-p-cym)(H(2)O)}](5-) (3)) have been synthesized and characterized. The binding mode of the d(6)-{M(II)L(3)(H(2)O)}(2+) moieties in these compounds is similar to that in the previously described [PW(11)O(39){Ru(eta(6)-p-cym)(H(2)O)}](5-) (4) complex: bidentate, on two nonequivalent oxygen atoms of the lacuna, leading to a loss of the C(s) symmetry of the parent anion, which thus plays the role of a prochiral bidentate ligand. The density functional theory (DFT) (B3PW91) computation of the lowest unoccupied molecular orbitals of the {ML(3)(H(2)O)}(2+) (M = Os, Ru; L(3) = fac-(DMSO)(3), eta(6)-C(6)H(6)) fragments reveals the similarities between their electrophilic properties. The origin of the regioselectivity of the grafting was investigated through a DFT (B3PW91) analysis of (i) the highest occupied molecular orbital of [alpha-PW(11)O(39)](7-) and (ii) the relative energies of the different potential regioisomers obtained by a bidentate grafting of the {ML(3)(H(2)O)}(2+) moiety onto the lacuna of [alpha-PW(11)O(39)](7-). The role of the water ligand in the stabilization of this peculiar structure was studied.
authors: Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, Université Pierre et Marie Curie, Case 42, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors: Danielle
authors: D
authors: Laurencin
authors: Richard
authors: R
authors: Villanneau
authors: Hélène
authors: H
authors: Gérard
authors: Anna
authors: A
authors: Proust