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Publications (2)15.27 Total impact

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    ABSTRACT: The reaction of Cr(C(6)H(6))(2) and 1,2,4,5-tetracyanopyrazine (TCNP) forms [Cr(C(6)H(6))(2)][TCNP], and TCNP is reduced and forms the eclipsed pi-[TCNP](2)(2-) dimer. Diamagnetic [TCNP](2)(2-) has an intradimer separation of 3.14(2) A. The intradimer C...C and N...N separations are 3.29(2) and 3.42(2) A, respectively, and increase with the distance from the center of the molecule, due to nitriles bending away from the plane of the molecule by 5 +/- 1 degrees. [TCNP](2)(2-) is best described by an atoms-in-molecules analysis as having a 2e(-)/8c C-C bond involving the four C atoms from each six-member ring. The results of B3LYP/6-31+G(d)-computed interactions indicate that the [TCNP](*-)...[TCNP](*-) interactions in an isolated [TCNP](2)(2-) are repulsive by 58.9 kcal/mol, and that the stability of [TCNP](2)(2-) primarily originates from [TCNP](*-)...cation(+) electrostatic interactions, whose sum (-209.8 kcal/mol) exceeds the sum of the repulsive [TCNP](*-)...[TCNP](*-) and cation(+)...cation(+) interactions (140.3 kcal/mol).
    Journal of the American Chemical Society 08/2009; 131(25):9070-5. · 10.68 Impact Factor
  • J. Novoa, P Stephens, M Weerasekare, W Shum, J Miller
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    ABSTRACT: HxK1-xMII[Ru2(CO3)4](H2O)y(MeOH)z (M = Mn, Fe, Co, Ni, Mg) were synthesized from the reaction of MII and K3[Ru2(CO3)4] in water and are isomorphous with an orthorhombic three-dimensional network structures based on e3-CO32- linkages to Ru2 moieties forming layers and also to trans-MII(OH2)4 sites forming linked chains that connect the layers. They, as well as non-isomorphous M = Cu, magnetically order as canted ferrimagnets with Tc = 4.4 {+-} 1.0 K. The presence of S = 0 MII = Mg(II) has essentially no effect on Tc suggesting that the main magnetic pathway does not occur the through MII-based chains, but only via Ru2{center_dot}...Ru2 linkages that reside in layers. This is a rare example of a magnet based upon a second row transition metal.
    Inorganic Chemistry 01/2009; · 4.59 Impact Factor