Series of manganese clusters derived from 2-pyridylcyanoxime with Mn3(II) (1), Mn4(II) (2a, b), Mn(II)4Mn(III)4 (3), Mn(II)2Mn(III)6Mn(IV)2 (4) and Mn(II)3Mn(III)6Mn(IV) (5) cores have been characterized. Dc magnetic measurements reveal antiferromagnetic coupling for 1-4 and dominant ferromagnetic interactions for 5 which shows the largest ground state reported to date in pyridyloximate chemistry (S = 14).
View Article and Find Full Text PDFAssembly of triangular {Mn(III)(3)(O)(salox)(3)}(+) fragments mediated by azido ligands, results in the dodecanuclear [Mn(12)O(4)(salox)(12)(N(3))(4)(MeOH)(4)(H(2)O)(2)] complex with S = 8 ground state and SMM response.
View Article and Find Full Text PDFReactions of 2,6-diacetylpyridine dioxime (dapdoH₂) with Mn(NO₃)₂ or Mn(SO₃CF₃)₂ under a variety of conditions or co-ligands yield compounds with the formula [Mn₆O₂(OMe)₂(dapdo)₂(dapdoH)₄](X)₂ in which X = NO₃⁻ (1) or SO₃CF₃⁻ (2), [Mn₈O₂(dapdo)₆(NO₃)₂]·H₂O (3) and [Mn(dapdoH₂)(N₃)₂](n) (4). Compounds 1, 3 and 4 were structurally characterized and equivalent structures for 1 and 2 were inferred from spectroscopic and analytical results. Compounds 1 and 2 consist of hexanuclear Mn₂(II)Mn₄(III) complexes whereas 3 consists of an octanuclear Mn₆(II)Mn₂(III) cluster in which the manganese atoms exhibit a rare bicapped elongated octahedral topology.
View Article and Find Full Text PDFControl of the dimensionality and nuclearity in pyraziloximatocopper(II) chemistry has been achieved by tuning of the donor properties of the counteranions.
View Article and Find Full Text PDFA new set of covalent atomic radii has been deduced from crystallographic data for most of the elements with atomic numbers up to 96. The proposed radii show a well behaved periodic dependence that allows us to interpolate a few radii for elements for which structural data is lacking, notably the noble gases. The proposed set of radii therefore fills most of the gaps and solves some inconsistencies in currently used covalent radii.
View Article and Find Full Text PDFA new family of functionalized ligands derived from norborn-5-ene-2,3-dicarboxylic anhydride has been used in Suzuki C-C cross-couplings between aryl boronic acids and aryl bromide derivatives in [BMI][PF(6)] (BMI=1-n-butyl-3-methyl-imidazolium), using palladium acetate as catalytic precursor. High conversions and yields are obtained when amine ligands containing hydroxy groups are involved. TEM analyses after catalysis show the formation of small nanoparticles, in contrast to the agglomerates observed when nanoparticles are intentionally preformed, with a consequent decrease in the catalytic activity in the latter case.
View Article and Find Full Text PDFStarch gel electrophoresis was used to analyze the allelic variability of four polymorphic loci (Lap-2, Lap-3, Pgm and Gpi) from a single population of Artemia franciscana (Kellogg, 1906) from the Great Salt Lake (Utah, USA), cultured under eight different experimental conditions. The organisms were cultured to the adult stage under a 2 x 2 x 2 experimental design (22 and 30 degrees C; 30 and 60 ppt salinity; and Dunaliella sp. and Spirulina sp.
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