Tetra­kis(μ2-ferrocene­carboxyl­ato-κ2 O:O′)bis­[(methanol-κO)copper(II)] methanol disolvate

The complex mol­ecule of the title compound, [Cu2Fe4(C5H5)4(C6H4O2)4(CH3OH)2]·2CH3OH, lies about an inversion centre and contains two centrosymetrically related CuII atoms bridged by four O:O′-bidentante ferrocene­carboxyl­ate anions, leading to a dimeric tetra­bridged unit with a paddle-wheel geometry. The CuII atom has a distorted square-pyramidal coordination environment with four O atoms from four ferrocene­carboxyl­ate ligands in basal positions and an O atom from a methanol mol­ecule in an apical position. One of the two crystallographically independent ferrocenyl groups has a staggered conformation, while the other is eclipsed. The mol­ecules are connected into a chain along the b axis by O—H⋯O hydrogen bonds involving coordinated and uncoordinated methanol mol­ecules and the O atom from a ferrocene­carboxyl­ate unit

Single-Crystal to Single-Crystal Reversible Transformations Induced by Thermal Dehydration in Keggin-Type Polyoxometalates Decorated with Copper(II)-Picolinate Complexes: The Structure Directing Role of Guanidinium

Three new hybrid inorganic-metalorganic compounds containing Keggin-type polyoxometalates, neutral copper(II)-picolinate complexes and guanidinium cations have been synthesized in bench conditions and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction: the isostructural [C(NH2)(3)](4)[{XW12O40}{Cu-2(pic)(4)}] . [Cu-2(pic)(4)(H2O)](2) .6H(2)O [X = Si (1), Ge (3)] and [C(NH2)(3)]8[{SiW12O40}(2){Cu(pic)(2)}3{Cu-2(pic)4(H2O)}(2)] .8H(2)O (2). The three compounds show a pronounced two-dimensional character owing to the structure-directing role of guanidinium. In 1 and 3, layers of [{XW12O40}{Cu-2(pic)(4)}] n(4n-) hybrid POM chains and layers of [Cu-2(pic)(4)(H2O)] complexes and [C(NH2)(3)](+) cations pack alternately along the z axis. The hydrogen-bonding network established by guanidinium leads to a trihexagonal tiling arrangement of all copper(II)-picolinate species. In contrast, layers of [C(NH2)(3)](+)-linked [{SiW12O40}(2){Cu(pic)(2)}(3)] n(8n-) double chains where each Keggin cluster displays a {Cu-2(pic)(4)(H2O)} moiety pointing at the intralamellar space are observed in 2. The thermal stability of 1-3 has been studied by thermogravimetric analyses and variable temperature powder X-ray diffraction. Compounds 1 and 3 undergo single-crystal to single-crystal transformations promoted by reversible dehydration processes and the structures of the corresponding anhydrous phases 1a and 3a have been established. Despite the fact that the [Cu-2(pic)(4)(H2O)] dimeric complexes split into [Cu( pic)(2)] monomers upon dehydration, the packing remains almost unaltered thanks to the preservation of the hydrogen-bonding network established by guanidinium and its associated Kagome-type lattice. Splitting of the dimeric complexes has been correlated with the electron paramagnetic resonance spectra.This work was funded by Eusko Jaurlaritza/Gobierno Vasco (grant IT477- 10 and predoctoral fellowship to A. P.), Ministerio de Economia y Competitividad (grant MAT2013-48366-C2-2P) and Universidad del Pais Vasco UPV/EHU (grant UFI11/53). Technical and human support provided by SGIker (UPV/EHU) is gratefully acknowledged

Osteosarcoma extraesquelético. Presentación de un caso

El osteosarcoma extraesquelético es un tumor maligno de alto grado que representa menos del 2% de los sarcomas de partes blandas y que afecta principalmente a personas entre la quinta y sexta década de la vida. Típicamente el diagnóstico es tardío, con un período síntomas-diagnóstico extenso, >6 meses en comparación con el del osteosarcoma convencional. Comunicamos el caso de un hombre de 43 años que acudió con una tumoración en la región glútea y el muslo izquierdo de un año de evolución. Luego de estudios complementarios y una biopsia no concluyentes, se procedió a la resección quirúrgica del tumor con márgenes amplios. El estudio histológico de la pieza indicó osteosarcoma extraesquelético. El paciente tuvo una evolución muy buena, sin elementos de recidiva local ni compromiso a distancia luego de 20 meses de seguimiento

trans-Diaquabis(pyridazine-3-carboxylato-κ2N2,O)copper(II)

In the title compound, [Cu(C5H3N2O2)2(H2O)2], the CuII ion, located on an inversion center, exhibits an octahedral coordination geometry. The equatorial plane is defined by two trans-related N,O-bidentate pyridazine-3-carboxylate ligands and the axial positions are occupied by two water molecules. In the crystal, molecules are connected by O—H...O hydrogen bonds between the water molecules and the noncoordinating carboxylate O atoms, forming layers parallel to the bc plane. The layers are stacked along the a axis by further O—H...O hydrogen bonds between the water molecules and the coordinating carboxylate O atoms. Weak C—H...O hydrogen bonds are also observed between the pyridazine rings and the water molecules and between the pyridazine rings and the non-coordinating carboxylate O atoms

Anatomic Posterolateral Corner Reconstruction Using Semitendinosus and Gracilis Autografts: Surgical Technique

An anatomically based posterolateral corner (PLC) reconstruction has emerged as a viable and clinically effective surgical technique for midsubstance ligamentous injuries in both the acute and chronic settings. There are several surgical techniques for PLC reconstruction; however, the classic anatomic reconstruction technique (LaPrade technique) is now considered the gold standard and was originally described using an Achilles tendon allograft. In this article, we describe a modified LaPrade autograft technique, in which the same tunnel position, graft passage, and fixation are used to reproduce the 3 primary stabilizers of the PLC. Instead of allografts, hamstring autografts are used while tunnel diameters and fixation devices are adapted to them. With the use of autograft tendons, difficulties related to graft length or asymmetry are encountered. We consider this technique a good alternative for an anatomically based PLC reconstruction, especially given the lower availability and higher cost of allograft tissues in several countries

Rearrangement of a Krebs-Type Polyoxometalate upon Coordination of N,O-Bis(bidentate) Ligands

Selective coordination of 2,3-pyzdc to the Krebs-type [{Ni­(H₂O)₃}₂(WO₂)₂(SbW₉O₃₃)₂]^10– anion promotes a skeletal rearrangement that results in the [(2,3-pyzdc)₂{NaNi₂(H₂O)₄Sb₂W₂₀O₇₀}₂]^22– (<b>Ni</b>_<b>4</b>) hybrid dimer showing a novel dinickel containing a 20-tungsto-2-antimonate­(III) framework stabilized by N,O-bis­(bidentate) bridging ligands. The solution stability and magnetism of <b>Ni</b>_<b>4</b> is discussed

Functionalization of Krebs-Type Polyoxometalates with N,O-Chelating Ligands: A Systematic Study

The first organic derivatives of 3d-metal-disubstituted Krebs-type polyoxometalates have been synthesized under mild bench conditions via straightforward replacement of labile aqua ligands with N,O-chelating planar anions on either preformed or in situ-generated precursors. Nine hybrid clusters containing carboxylate derivatives of five- or six-membered aromatic N-heterocycles as antenna ligands have been obtained as pure crystalline phases and characterized by elemental and thermal analyses, infrared spectroscopy, and single-crystal X-ray diffraction. They all show the general formula [{M^IIL­(H₂O)}₂(WO₂)₂(<i>B</i>-β-XW₉O₃₃)₂]^<i>n–</i> and can be classified as follows: <b>1-SbM</b>, where L = 1<i>H</i>-imidazole-4-carboxylate (imc), X = Sb^III, <i>n</i> = 12, and M^II = Mn, Co, Ni, Zn; <b>1-TeM</b>, where L = imc, X = Te^IV, <i>n</i> = 10, and M^II = Mn, Co; <b>2-SbNi</b>, where L = 1<i>H</i>-pyrazole-3-carboxylate (pzc), X = Sb^III, <i>n</i> = 12, and M^II = Ni; and <b>3-SbM</b>, where L = pyrazine-2-carboxylate (pyzc), X =Sb^III, <i>n</i> = 12, and M^II = Co, Zn. The 3d-metal-disubstituted tungstotellurate­(IV) skeleton of compounds <b>1-TeM</b> is unprecedented in polyoxometalate chemistry. The stability of these hybrid Krebs-type species in aqueous solution has been confirmed by ¹H NMR spectroscopy performed on the diamagnetic <b>1-SbZn</b> and <b>3-SbZn</b> derivatives. Our systematic study of the reactivity of disubtituted Krebs-type polyoxotungstates toward diazole-, pyridine-, and diazinecarboxylates demonstrates that organic derivatization is strongly dependent on the nature of the ligand, as follows: imc displays a “universal ligand” character, as functionalization takes place regardless of the external 3d metal and heteroatom; pzc and pyzc show selectivity toward specific 3d metals; pyridazine-3-carboxylate and pyrimidine-4-carboxylate promote partial decomposition of specific precursors, leading to [M^IIL₂(H₂O)₂] complexes; and picolinate is inert under all conditions tested