Role of estuarine habitats for the feeding ecology of the European eel (Anguilla anguilla L.).

This study aims to characterize and compare the feeding ecology of the European eels (Anguilla anguilla L.) during the continental phase (i.e.

Dependence of the interaction mechanisms between L-serine and O-phospho-L-serine with calcium hydroxyapatite and copper modified hydroxyapatite in relation with the acidity of aqueous medium.

Motivated by the role of copper ions in biological processes the aim of this study was to elucidate the impact of copper ions bound to hydroxyapatite on L-serine (L-Ser) and O-phospho-L-serine (O-Ph-L-Ser) adsorption at different acidity of aqueous solutions. The adsorption phenomenon was studied by FTIR, UV, and AA spectroscopy, XRD and thermal analysis methods together with the evolved gases analysis taking into consideration the ionic state of the amino acids as well as the apatite surface state, which are tightly correlated with the solution pH. In acidic solution, the main process involves apatite dissolution releasing calcium and copper ions.

Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L.

Molecular composition and biodegradability of soil organic matter: a case study comparing two new England forest types.

Soil organic matter (SOM) is involved in many important soil processes such as carbon sequestration and the solubility of plant nutrients and metals. Ultrahigh resolution mass spectrometry was used to determine the influence of forest vegetation type and soil depth on the molecular composition of the water-extractable organic matter (WEOM) fraction. Contrasting the upper 0-5 cm with the 25-50 cm B horizon depth increment, the relative abundance of lipids and carbohydrates significantly increased, whereas condensed aromatics and tannins significantly decreased for the deciduous stand WEOM.

(S)-(-)-(2-MeBu)N(Pr)₂MeI salt as template in the enantioselective synthesis of the enantiopure two-dimensional (S)-(-)-(2-MeBu)N(Pr)₂Me[ΛMnΔCr(C₂O₄)₃] ferromagnet.

We describe herein the synthesis of (rac)- or enantiopure (S)-(-)-(2-MeBu)N(Pr)₂MeI ammonium salts. These racemic and enantiopure ammonium salts were used as cationic templates to obtain new two-dimensional (2D) ferromagnets [(rac)-(2-MeBu)N(Pr)₂Me][MnCr(C₂O₄)₃] and [(S)-(-)-(2-MeBu)N(Pr)₂Me][ΔMnΛ nCr(C₂O₄)₃]. The absolute configuration of the hexacoordinated Cr(III) metallic ion in the enantiopure 2D network was determined by a circular dichroism measurement.

The fruitful introduction of chirality and control of absolute configurations in molecular magnets.

In this critical review, it is shown how the introduction of chirality and the control of the absolute configurations of chiral elements in molecular magnets allow obtaining enantiopure chiral magnets (ECM), an archetype of multifunctional materials. This task has been recognised as a major challenge for both chemists and physicists of molecular magnetism. To reach this goal, the former have combined the rational approaches towards molecular-based magnets and of enantiopure metal-organic frameworks.

Large magnetization-induced second harmonic generation in an enantiopure chiral magnet.

The absence of centrosymmetry in the enantiopure chiral magnet [N(CH(3))(n-C(3)H(7))(2)(C*H(CH(3))C(2)H(5))][Mn(II)Cr(III)(ox)(3)] allows the observation of bulk second harmonic generation (SHG) in this material. At low temperature, the onset of magnetization gives birth to a magnetization-induced SHG (MSHG) contribution. With an angular shift of 13.

Switching between gap and overlap pro-saccades: cost or benefit?

Triggering of saccades depends on the task: in the gap task, fixation point switches off and target appears after a gap period; in the overlap task, target appears while fixation point is still on. Saccade latencies are shorter in the gap task, due to fixation disengagement and advanced movement preparation during the gap. The two modes of initiation are also hypothesized to be subtended by different cortical-subcortical circuits.

Sorption of tartrate ions to lanthanum (III)-modified calcium fluor- and hydroxyapatite.

The present article details the formation of lanthanum-modified apatites and the binding process of tartrate ions with these obtained apatites. Chemical analyses, FT-IR and (31)P NMR spectroscopies, XRD powder, TGA, and TEM analyses were employed for studying the reaction between Ca(10)(PO(4))(6)(OH)(2) (HAp) or Ca(10)(PO(4))(6)(F)(2) (FAp) and LaCl(3). The reaction was found to take place mainly through partial dissolution of the apatite followed by precipitation of a new phase containing lanthanum phosphate.

Strong magneto-chiral dichroism in enantiopure chiral ferromagnets.

As materials science is moving towards the synthesis, the study and the processing of new materials exhibiting well-defined and complex functions, the synthesis of new multifunctional materials is one of the important challenges. One of these complex physical properties is magneto-chiral dichroism which arises, at second order, from the coexistence of spatial asymmetry and magnetization in a material. Herein we report the first measurement of strong magneto-chiral dichroism in an enantiopure chiral ferromagnet.

Enantiomerically pure quaternary ammonium salts with a chiral alkyl chain N(CH3)(n-C3H7)2(sec-C4H9)I: synthesis and physical studies.

A pair of enantiomerically pure quaternary ammonium salts with a chiral side chain, methyl-(R)-(1-methylpropyl)di(n-propyl)ammonium iodide 1 and methyl-(S)-(1-methylpropyl)di(n-propyl)ammonium iodide 2, and the related racemate, methyl-(rac)-(1-methylpropyl)di(n-propyl)ammonium iodide 3, were synthesized through a reductive alkylation procedure, starting from enantiomerically pure and, also, racemic forms of (rac)-(1-methylpropyl)amine. A spectroscopic chiroptical signature in solution was provided by the Raman optical activity spectra of compounds 1 and 2. The crystallographic structures of 1, 2, and 3 were examined by single crystal X-ray diffraction.

Six-fold oxygen-coordinated triplet (S = 1) palladium(II) moieties templated by tris(bipyridine)ruthenium(II) ions.

Tris(bipyridine)ruthenium(II) is used as a templating agent to insert palladium(II) into three-dimensional oxalate-based networks. The templated-assembly of [Ru(bpy)(3)][Pd(2)(ox)(3)] (Pd(2)) and [Ru(bpy)(3)][PdMn(ox)(3)] (PdMn) is described. The latter compound is structurally characterized by powder X-ray diffraction and X-ray absorption spectroscopy.

A new glance at ruthenium sorption mechanism on hydroxy, carbonate, and fluor apatites: Analytical and structural studies.

The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis.

A new family of mono- and dicarboxylic ruthenium complexes [Ru(DIP)2(L2)]2+ (DIP = 4,7-diphenyl-1,10-phenanthroline): synthesis, solution behavior, and X-ray molecular structure of trans-[Ru(DIP)2(MeOH)2][OTf]2.

A new family of ruthenium complexes of general formula [Ru(DIP)2(L2)]2+, where DIP = 4,7-diphenyl-1,10-phenanthroline, a bidentate ligand with an extended aromatic system, was prepared and fully characterized. When L is a monodentate ligand, the following complexes were obtained: L = CF3SO3(-1) (2), CH3CN (3), and MeOH (4). When L2 is a bidentate ligand, the compounds [Ru(DIP)2(Hcmbpy)][Cl]2 (5) and [Ru(DIP)2(H2dcbpy)][Cl]2 (6) were prepared (Hcmbpy = 4-carboxy-4'-methyl-2,2-bipyridine, H2dcbpy = 4,4'-dicarboxy-2,2'-bipyridine).

Efficient DNA binding by optically Pure Ruthenium Tris(bipyridyl) complexes incorporating carboxylic functionalities. Solution and structural analysis.

Herein, we report on the binding of optically pure ruthenium complexes Delta- or Lambda-[Ru(bpy)(2)(L-L)][PF(6)](2) [L-L = Hcmbpy = 4-carboxy-4'-methyl-2,2'-bipyridine (1), L-L = H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine (2)] to DNA. The binding constants of the two enantiomeric Delta-1 and Lambda-1 complexes to DNA were estimated from titration monitored by (1)H NMR spectroscopy. 2D transferred NOESY (TRNOESY) experiments support the conclusion that Delta-1 and Lambda-1 bind to DNA and that an intermediate-to-fast exchange occurs between bound and free Ru(II) complex.

Enantioselective self-assembly of bimetallic [Mn(II) (delta)-Cr(III)(C2O4)3]- and [Mn(II) (lambda)-Cr(III)(C2O4)3]- layered anionic networks templated by the optically active (Rp)- and (Sp)-[1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5]+ ions.

The ferrocenic ammonium (Rp)- and (Sp)-[1-CH2NR(3-)-2-CH3-C5H3Fe-C5H5] iodide salts with R=CH3, C2H5, n-C3H7, n-C4H9, were synthesized starting from the (Rp)- and (Sp)-[1-CH2N(CH3)2-2-CH3-C5H3Fe-C5H5] amines obtained in their optically active forms through asymmetric cyclopalladation of [C5H5Fe-C5H4CH2N(CH3)2]. 1H NMR studies of these planar chiral 1,2-disubstituted ferrocenic ammonium iodide salts in the presence of the (Delta)-(tris(tetrachlorobenzenediolato)phosphate(V) anion), [(Delta)-Trisphat] support the formation of specific diastereomeric ion pairs. Such intermolecular interactions can be related to the self-assembly of the two-dimensional optically active compounds [[(Sp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Delta)-Cr(C2O4)3]] and [[(Rp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Lambda)-Cr(C2O4)3]] starting from the resolved (Rp)- and (Sp)-[1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5]+ ion associated to the racemic anionic building block rac-[Cr(C2O4)3]3- and Mn2+.

Enantiospecific synthesis of delta and lambda [Ru(bpy)(2)ppy](+) and [Ru(bpy)(2)quo](+) (bpy = 2,2'-bipyridine, ppy = phenylpyridine-H(+), quo = 8-hydroxyquinolate): (1)H and (13)C NMR studies and X-ray structure determination of rac-[Ru(bpy)(2)quo]PF(6).

In this paper, we describe the enantiospecific synthesis and the complete characterization of the two hexacoordinated ruthenium(II) monocations [Ru(bpy)(2)ppy](+) and [Ru(bpy)(2)quo](+) (bpy = 2,2'-bipyridine, ppy = phenylpyridine-H(+), quo = 8-hydroxyquinolate) in their enantiomeric Delta and Lambda forms. The corresponding enantiomeric excesses (ee's) are determined by (1)H NMR using pure Delta-Trisphat (tris(tetrachlorobenzenedialato)phosphate(V) anion) as a chiral (1)H NMR shift reagent. A complete (1)H and (13)C NMR study has been carried out on rac-[Ru(bpy)(2)ppy]PF(6) and rac-[Ru(bpy)(2)quo]PF(6).

Optically active molecule-based magnets: enantioselective self-assembling, optical, and magnetic properties.

In this short communication we describe the synthesis and the optical and magnetic properties of optically active three dimensional (3D) bimetallic [Cr-Mn] networks [[Delta Cr(III) Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(3)]ClO(4)](n)1 - Delta, [[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II) (bpy)(3)]ClO(4)](n) 1 - Lambda and [[Delta Cr(III)Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(2)p p y]](n) 2 - Delta,[[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II)(bpy)(2)ppy]](n) 2 - Lambda (ox = oxalate, bpy = bipyridine, ppy = phenyl-pyridine).

Enantioselective Synthesis of Optically Active Polymeric Homo- and Bimetallic Oxalate-Bridged Networks [M(2)(ox)(3)](n)().

The synthesis of the enantiomeric forms of the two- and three-dimensional polymers: {[NBu(4)][MnCr(ox)(3)]}(n)() (1) (Bu = n-butyl, ox = oxalate), {[M(bpy)(3))][LiCr(ox)(3)]}(n)() (M = Ni (2), Ru (4)) (bpy = 2,2'-bipyridine), {[M(bpy)(3))][Mn(2)(ox)(3)]}(n)() (M = Ni (3), Ru (5)) using resolved [Cr(ox)(3)](3)(-) and [M(bpy)(3)](2+) (M = Ni, Ru) species as chiral building blocks, and their structural characterization are reported. The optical activity of these systems arises from the helical chirality of the tris-chelated subunits with Delta or Lambda configurations. Bimetallic two-dimensional optically active network 1 results from the stacking of similar metallo-oxalate honeycomblike layers containing [Cr(ox)(3)](3)(-) units of the same chirality.

Rational design of three-dimensional (3D) optically active molecule-based magnets: synthesis, structure, optical and magnetic properties of ([Ru(bpy)3](2+), ClO4(-), [Mn(II) Cr(III)(ox)3](-))n and ([Ru(bpy)2ppy](+), [M(II)Cr(III)(ox)3](-))n, with M(II) = Mn(II), Ni(II). X-ray structure of ([deltaRu(bpy)3](2+), ClO4(-), [deltaMn(II)DeltaCr(III)(ox)3](-))n and ([lambdaRu(bpy)2ppy)](+), [lambdaMn(II)lambdaCr(III)(ox)3](-))n.

To elucidate the relation between structural and magnetic properties, we have synthesized molecular materials having both Cotton effects and a ferromagnetic long range order. Such optically active 3D molecule-based magnets were rationally designed using the enantioselective template effect of optically active cations, namely Delta or Lambda [Ru(bpy)3, ClO4](+) or Delta or Lambda [Ru(bpy)3ppy](+) (bpy = bipyridine; ppy = phenylpyridine). Such cations are able to template the formation of optically active 3D anionic networks in which transition metal ions (Cr-Mn) and (Cr-Ni) are connected by oxalate ligands (ox).

Cobalt-complexed conjugated diyne salts: a family of rigid masked dielectrophiles. Syntheses, structures, and double nucleophilic substitutions.

A family of dicationic diyne salts of the general formula [(Co2(CO)6)2-mu,eta2,eta2-(Nu-CH2C(triple bond)C-C(triple bond)CCH2-Nu)][BF4]2 [Nu = SMe2 (3); Nu = NC6H7, 3-picoline, (5); Nu = NC9H7, quinoline (7)] were prepared and fully characterized. Three X-ray molecular structures of 3, 5, and the neutral starting material 2,4-hexadiyne-1,6-diol complex [(Co2(CO)6)2-mu,eta2,eta2-(HO-CH2C(triple bond)C-C(triple bond)CCH2-OH)] (1) are presented. Complex 1 crystallizes in the triclinic space group P1 with a = 14.

Cobalt-Induced C-N and C-C Bond Formation via Metal-Stabilized alpha-CF(3) Carbenium Ion.

An alpha-CF(3)-carbenium ion stabilized by a bimetallic [Co-Co] cluster was prepared and isolated in good yield, starting from the corresponding alcohol by action of HBF(4)/Et(2)O. C-N and C-C bonds with nitrogen and carbon nucleophiles could be easily formed. Subsequent decomplexation gave the free substituted beta-CF(3) alkynes in good yields.

Synthesis of cobalt carbonyl complexes of cortisol and testosterone. Study of their recognition by specific polyclonal antibodies.

We have synthesized organometallic complexes of steroids (cortisol, testosterone, dihydrotestosterone) for potential use as tracers in nonisotopic carbonyl-metal immunoassays (CMIA). An ethynyl/CO2(CO)6 fragment at the end of a five-atom spacer was coupled to position 3 of the steroid skeleton. In the case of cortisol, we exploited the difference in reactivity of the ketone and enone functions toward amines in order to form an enamine which was then made to react with carboxymethylamine to yield 3-[(carboxymethyl)oxime] steroid.