Biogeography of a Global Plant Invader: From the Evolutionary History to Future Distributions.

Biological invasions pose a global challenge, affecting ecosystems worldwide and human societies. Knowledge of the evolutionary history of invasive species is critical to understanding their current invasion success and projecting their future spread. However, to date, few studies have addressed the evolutionary history and potential future spread of invaders simultaneously.

Crystal structure of CsGdNbClO in the structural evolution of niobium oxychlorides with octa-hedral Nb-cluster units.

CsGdNbClO, dicaesium gadolinium hexa-niobium penta-deca-chloride trioxide, was synthesized by solid-state reactions starting from a stoichiometric mixture of CsCl, GdO, Nb, NbCl, and NbO. The crystal structure is based on octa-hedral Nb cluster units (point group symmetry 3.2) with composition [(NbCl O )Cl ] where and denote inner and outer ligands.

Stability hierarchy between Piracetam forms I, II, and III from experimental pressure-temperature diagrams and topological inferences.

The trimorphism of the active pharmaceutical ingredient piracetam is a famous case of polymorphism that has been frequently revisited by many researchers. The phase relationships between forms I, II, and III were ambiguous because they seemed to depend on the heating rate of the DSC and on the history of the samples or they have not been observed at all (equilibrium II-III). In the present paper, piezo-thermal analysis and high-pressure differential thermal analysis have been used to elucidate the positions of the different solid-solid and solid-liquid equilibria.

Synthesis, structural evolution, and electrical properties of the novel Mo12 cluster compounds K(1+x)Mo12S14 (x = 0, 1.1, 1.3, and 1.6) with a tunnel structure.

The new structural type (1) K(2.3)Mo12S14 was prepared by solid-state reaction at 1500 degrees C in a sealed molybdenum crucible. The compound crystallizes in the trigonal space group P1c, Z = 2, (1) a = 9.

Synthesis and crystal and electronic structures of the Na2(Sc4Nb2)(Nb6O12)3 octahedral niobium cluster oxide. Structural correlations between AnBM6L12(Z) series and Chevrel Phases.

We report here the synthesis and crystal and electronic structures of the Na(2)(Sc(4)Nb(2))(Nb(6)O(12))(3) niobium oxide whose structure is related to that of Ti(2)Nb(6)O(12). It constitutes a new member of the larger A(n)()BM(6)L(12)(Z) families (A = monovalent cation located in tetrahedral cavities of units, B = monovalent or trivalent cations located in octahedral cavities of units, M = rare earth, Zr, or Nb, Z = interstitial except for M = Nb). The structural relationships between the A(n)BM(6)L(12)(Z) series (M(6)L(i)(12)L(a)(6) unit-based compounds with a M(6)L(i)(6)L(i-a)(6/2)L(a-i)(6/2) cluster framework) and Chevrel Phases (M(6)L(i)(8)L(a)(6) unit-based compounds with a M(6)L(i)(2)L(i-a)(6/2)L(a-i)(6/2) cluster framework) are shown in terms of M(6)L(18) and M(6)L(14) unit packing.

The versatility of pentalene coordination to transition metals: a density functional theory investigation.

DFT calculations with full geometry optimization have been carried out on a series of real and hypothetical compounds of the type [CpM(C8H6)], [(CO)3M(C8H6)], [M(C8H6)2], [(CpM)2(C8H6)], [[(CO)3M]2(C8H6)], and [M2(C8H6)2] (M = transition metal). The bonding in all the currently known compounds is rationalized, as well as in the (so far) hypothetical stable complexes. Depending on the electron count and the nature of the metal(s), eta2 (predicted), eta3, eta5, eta8, or intermediate coordination modes can be adopted.

In situ generation of carboxylate: an efficient strategy for a one-pot synthesis of homo- and heterometallic polynuclear complexes.

An efficient strategy for synthesis of a wide range of homo- and heterometallic polynuclear complexes is proposed. The synthesis protocol consists of a two-step one-pot reaction. The first step is the in situ generation of carboxylate anions via oxidation of aromatic aldehydes by metal nitrates in air.

Synthesis, structure, and magnetism of heterometallic carboxylate complexes [MnIII2M(II)4O2(PhCOO)10(DMF)4], M = Mn(II), Co(II), Ni(II).

Three new homo- and heterometallic hexanuclear complexes [Mn(2)M(II)(4)O(2)(PhCOO)(10)(DMF)(4)] (with M = Mn (1), Co (2) or Ni (3) and DMF = dimethylformamide) have been synthesized by redox generation of benzoate ligands from benzaldehyde in a one-pot reaction. All of the compounds are isostructural and crystallize in the I-42d space group of the tetragonal system, data for 1: a = 27.2249(8) Angstroms, c = 25.

Gentamicin-loaded calcium carbonate materials: comparison of two drug-loading modes.

Synthetic aragonite-based porous materials were drug loaded with gentamicin sulphate, an antibiotic active on Staphylococcus aureus responsible for osteomyelitis. Drug loading was accomplished by two different ways: by integration of gentamicin in material during processing or by soaking material into gentamicin solutions. We first investigated the influence of drug loading on compressive strength of materials.

Synthesis, crystal structure from single-crystal and powder X-ray diffraction data, and thermal behavior of mixed potassium lanthanide squarates: thermal transformations of layered [Ln(H2O)6]K(H2C4O4)(C4O4)2 into pillared LnK(C4O4)2 (Ln = Y, La, Gd, Er).

A new series of mixed potassium and rare-earth squarates, [Ln(H(2)O)(6)]K(H(2)C(4)O(4))(C(4)O(4))(2) (Ln = Y, La, Gd, Er), has been synthesized and structurally characterized from single-crystal X-ray diffraction and spectroscopic analyses. The yttrium-based compound crystallizes with a monoclinic symmetry, space group C2/c [a = 8.3341(2) A, b = 37.

Bonding in tetrahedral Cu4(mu3-X)4L4 copper(I) clusters: a DFT investigation.

DFT calculations on Cu(4)(mu3-X)4L4 (X = H, CH(3), CCH, F, Cl, Br, I; L = NH(3), PH(3)) indicate that, regardless of its nature, X- acts essentially as a two-electron sigma-type ligand and that the covalent part of the Cu...

Synthesis and characterization of hypoelectronic rhenaboranes. Analysis of the geometric and electronic structures of species following neither borane nor metal cluster electron-counting paradigms.

The reaction of (CpReH(2))(2)B(4)H(4) with monoborane leads to the sequential formation of (CpRe)(2)B(n)()H(n)() (n = 7-10, 1-4). These species adopt closed deltahedra with the same total connectivities as the closo-borane anions [B(n)()H(n)()](2)(-), n = 9-12, but with flattened geometries rather than spherical shapes. These rhenaborane clusters are characterized by high metal coordination numbers, Re-Re cross-cluster distances within the Re-Re single bond range, and formal cluster electron counts three skeletal electron pairs short of that required for a canonical closo-structure of the same nuclearity.

Syntheses and structural, physical, and theoretical studies of the novel isostructural Mo9 cluster compounds Ag(2.6)CsMo9Se11, Ag(4.1)ClMo9Se11, and h-Mo9Se11 with tunnel structures.

The new isostructural compounds Ag(2.6)CsMo9Se11 (1) and Ag(4.1)ClMo9Se11 (2) were prepared by solid-state reaction in evacuated sealed silica tubes at 1200 degrees C and 860 degrees C, respectively.

Synthesis and characterization of Mo(6) chalcobromides and cyano-substituted compounds built from a novel [(Mo(6)Br(i)(6)Y(i)(2))L(a)(6)](n)()(-) discrete cluster unit (Y(i) = S or Se and L(a) = Br or CN).

The syntheses, crystal structures determined by single-crystal X-ray diffraction, and characterizations of new Mo(6) cluster chalcobromides and cyano-substituted compounds with 24 valence electrons per Mo(6) cluster (VEC = 24), are presented in this work. The structures of Cs(4)Mo(6)Br(12)S(2) and Cs(4)Mo(6)Br(12)Se(2) prepared by solid state routes are based on the novel [(Mo(6)Br(i)(6)Y(i)(2))Br(a)(6)](4)(-) (Y = S, Se) discrete units in which two chalcogen and six bromine ligands randomly occupy the inner positions, while the six apical ones are fully occupied by bromine atoms. The interaction of these two compounds with aqueous KCN solution results in apical ligand exchange giving the two first Mo(6) cyano-chalcohalides: Cs(0.

A novel layered niobium oxychloride compound based on Nb2 pairs and Nb6 octahedral clusters: synthesis and crystal and electronic structures of Nb10Cl16O7.

The synthesis, single crystal structure determination, and electronic structure of Nb10Cl16O7, the first Nb6 oxychloride stabilized without countercation, are reported in this work. The crystal structure is very original since it consists of layers built up from both Nb6 octahedral clusters and Nb2 pairs. The Nb6Oi6Cli6Cla6 and Nb2(mu2-Cl)2Cl4O4 units form [Nb6Cli6Oi4O(i-i)(2/2)Cl(a-a)(4/2)Cla2]infinity infinite chains and [(Nb2(mu2-Cl)2O(2/2)Cl(4/2)O2)2]infinity double chains, respectively, that are interconnected by shared oxygen and chlorine ligands leading to layers.

Reassessment of methyl rotation barriers and conformations by correlated quantum chemistry methods.

Internal rotations of the methyl group in ortho-substituted and 2,6-disubstituted toluenes in their ground state have been investigated by means of various ab initio quantum chemistry methods. Computed barriers at the Hartree-Fock (HF) level using medium sized basis sets agreed reasonably with experimental results in the case of the studied ortho-substituted toluenes. However, this agreement worsens when using very large basis sets.

Structural trends and the electronic structure of the rare-earth oxomolybdates RMo(5)O(8) (R = La, Ce, Pr, Nd, Sm, Eu and Gd) containing chains of bioctahedral Mo(10) clusters.

The crystal structures of the rare-earth members of the series RMo(5)O(8) (R = Ce to Eu) have been investigated and compared with those of the La and Gd members previously published in order to understand the influences of the size and the charge of the cation on the different Mo-Mo bonds. The RMo(5)O(8) compounds crystallize in the monoclinic space group P2(1)/c. Their crystal structure is characterized by bioctahedral Mo(10) clusters forming extended chains.

The low-temperature phase of 1,3-dibromo-2,4,6-trimethylbenzene: a single-crystal neutron diffraction study at 120 and 14 K.

In the low-temperature phase of dibromomesitylene (1,3-dibromo-2,4,6-trimethylbenzene), C(9)H(10)Br(2), the molecule deviates significantly from the C(3h) molecular symmetry encountered in tribromomesitylene (1,3,5-tribromo-2,4,6-trimethylbenzene), even for the endocyclic bond angles. An apparent C(2v) molecular symmetry is observed. The angle between the normal to the molecular plane and the normal to the (100) plane is approximately 20 degrees.

Characterisation and quantification of angiogenesis in beta-tricalcium phosphate implants by immunohistochemistry and transmission electron microscopy.

The aim of this study is the histological characterisation of angiogenesis in a macroporous biomaterial with quantification techniques used in oncology. Porous tricalcium phosphate implants were seated in the tibias of 12 rabbits. This work allows (1) morphological study with photonic microscopy, transmission electron microscopic and immunohistochemistry labelling for (2) quantification of vascularisation using anti-CD31 monoclonal antibody (3) quantification of proliferation using anti-PCNA polyclonal antibody (4) study of two angiogenic growth factors: VEGF and FGF-2.

First radical cation salt of paramagnetic transition metal complex containing TTF as ligand, [Cu(II)(hfac)2(TTF-py)2](PF6) x 2CH2Cl2 (hfac = hexafluoroacetylacetonate and TTF-py = 4-(2-tetrathiafulvalenyl-ethenyl)pyridine).

The preparation, X-ray crystal structure, EPR data, and magnetic measurement of [Cu(II)(hfac)(2)(TTF-py)(2)](PF(6)).2CH(2)Cl(2), a novel material where the conducting and the localized spin systems are covalently linked through conjugated bridges, are reported. The partial oxidation of the TTF-type organic donor ligand yielded the first radical cation salt of a paramagnetic transition metal complex.

Synthesis, crystal structure, and characterization of the first Nb(3) triangular cluster compound bonded to fluorine ligands: association of Nb(3)I(i)F(i)(3)F(a)(8)L(a) units and Nb(IV)L(6) Octahedra with L=O and F.

The synthesis and the crystal structure of the first compound containing Nb(3) triangular clusters bonded to fluorine ligands are presented in this work. The structure of Nb(3)IF(7)L(NbL(2))(0.25) with L = O and F, determined by single-crystal X-ray diffraction, is based on a Nb(3)I(i)F(i)(3)F(a)(8)L(a) unit and a NbL(6) octahedron (tetragonal, space group I4/m, a = 13.

Bulk weak ferromagnet in ferrimagnetic chains of organic-inorganic hybrid materials based on BDH-TTP and paramagnetic thiocyanato complex anions: (BDH-TTP)[M(isoq)(2)(NCS)(4)], M = Cr(III), Fe(III).

The preparation, X-ray crystal structures, and magnetic properties of two new isostructural charge transfer salts, (BDH-TTP)M(isoq)(2)(NCS)(4) (M = Cr(III) (1), Fe(III) (2), BDH-TTP = 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene, isoq = isoquinoline), are reported. Crystal data for 1: monoclinic, space group C2/c (#15), a = 16.1363(9) A, b = 19.