Search results for "Organometallic Compound"
showing 10 items of 245 documents
The first unpaired electron placed inside a C3-symmetry P-chirogenic cluster
2010
The Pd(3)(dppm*)(3)(CO)(n+) enantiomers (n = 2 (2), 1 (3)) were prepared either from (R,R)- or (S,S)-P-chirogenic bis(phenyl-m-xylylphosphino)methane (dppm*; 1) and Pd(OAc)(2) in the presence of CF(3)CO(2)H, CO and water (n = 2), and then by reductive electrolysis (n = 1). The stable enantiomeric [Pd(3)((S,S)-dppm*)(3)(CO)](+)˙ (3), is the first C(3)-symmetry radical-cation M-M bonded cluster, therefore the odd electron is delocalized onto the Pd(3) frame within this symmetry. The novel chiral species have been characterized by circular dichroism (CD) of both enantiomers of the Pd(3)(dppm*)(3)(CO)(2+) clusters (2) and by EPR spectroscopy for the Pd(3)((S,S)-dppm*)(3)(CO)(+)˙ paramagnetic co…
The new frontier of bone formation: a breakthrough in postmenopausal osteoporosis?
2009
Osteoporosis is a chronic disease that accelerates after menopause in many women. Most of the pharmacologic attempts to control the disease, such as hormone therapy, have emphasized the constraint of bone resorption. Since recent years have witnessed important advances in the field of bone formation, this review aims to update the present knowledge on the mechanisms affecting osteoblastogenesis and on the therapeutic results achieved by recently approved drugs.We sought peer-reviewed, full-length basic and clinical articles published between 1995 and May 2008 using a PubMed search strategy, with the terms osteoporosis and osteoblast, osteoporosis and strontium ranelate, and osteoporosis and…
Dilution-Triggered SMM Behavior under Zero Field in a Luminescent Zn2Dy2 Tetranuclear Complex Incorporating Carbonato-Bridging Ligands Derived from A…
2013
The synthesis, structure, magnetic, and luminescence properties of the Zn2Dy2 tetranuclear complex of formula {(mu(3)-CO3)2[Zn(mu-L)Dy(NO3)}(2)}center dot 4CH(3)OH (1), where H2L is the compartmental ligand N,N',N"-trimethyl-N,N"-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine, are reported. The carbonate anions that bridge two Zn(mu-L)Dy units come from the atmospheric CO2 fixation in a basic medium. Fast quantum tunneling relaxation of the magnetization (QTM) is very effective in this compound, so that single-molecule magnet (SMM) behavior is only observed in the presence of an applied dc field of 1000 Oe, which is able to partly suppress the QTM relaxation process. At variance,…
Crystal structure of [Cu(N-quinolin-8-yl-p-toluenesulfonamidate)2]: study of its interaction with DNA and hydrogen peroxide
2001
A new copper complex with N-quinolin-8-yl-p-toulenesulfonamide has been prepared and characterised. The compound crystallises in the triclinic system, space group P1, with a=13.457(3), b=15.067(5), c=18.589(3) A; α=112.05(2), β=93.92(2), γ=108.30(2)° and Z=4. The geometry of the Cu(II) ion is distorted square planar. The N-quinolin-8-yl-p-toulenesulfonamidate anion behaves as a bidentate ligand through the N s u l f o n a m i d a t e and N q u i n o l i n e atoms. The complex does not cleave DNA in the presence of hydrogen peroxide.
The CO-releasing molecule CORM-3 protects against articular degradation in the K/BxN serum transfer arthritis model.
2010
Contains fulltext : 89015.pdf (Publisher’s version ) (Closed access) Carbon monoxide-releasing molecules can counteract inflammatory responses. The aim of this study was to investigate whether tricarbonylchloro(glycinate)ruthenium (II) (CORM-3) is able to control the effector phase of experimental arthritis. Arthritis was induced in C57Black-6 mice by an intraperitoneal injection of serum from arthritic K/BxN mice. CORM-3 was administered intraperitoneally at 10 mg/kg/day (5 mg/kg twice a day) from days 0 to 10 and animals were sacrificed on day 11. Serum levels of osteocalcin and prostanoids were measured by enzyme-linked immunosorbent assay and radioimmunoassay. Gene expression was determ…
Cubane-Type Mo3FeS44+,5+ Complexes Containing Outer Diphosphane Ligands: Ligand Substitution Reactions, Spectroscopic Studies, and Electronic Structu…
2012
A general protocol to access Mo(3)FeS(4)(4+) clusters selectively modified at the Fe coordination site is presented starting from the all-chlorine Mo(3)(FeCl)S(4)(dmpe)(3)Cl(3) (1) [dmpe = 1,2-bis(dimethylphosphane-ethane)] cluster and tetrabutylammonium salts (n-Bu(4)NX) (X = CN(-), N(3)(-), and PhS(-)). Clusters Mo(3)(FeX)S(4)(dmpe)(3)Cl(3) [X = CN(-) (2), N(3)(-) (3), and PhS(-) (4)] are prepared in high yield, and comparison of geometric and redox features upon modification of the coordination environment at the Fe site at parity of ligands at the Mo sites is also presented. The existence of the cubane-type Mo(3)FeS(4)(4+,5+) redox couple is demonstrated by cyclic voltammetry and for co…
Sequestration of organometallic compounds by natural organic matter. binding of trimethyltin(IV) by fulvic and alginic acids
2006
The binding capacity of fulvic and alginic acids towards trimethyl tin(IV) cation was quantitatively determined in order to evaluate the sequestering ability of toxic organometallic compounds by natural organic matter. Investigations were performed in the pH range of natural waters (5–8.5) where the carboxylate groups, largely present in both sequestering agents, are the main binding sites. A chemical interaction model, according to which both the protonation of polyelectrolyte ligands and the hydrolysis of the organotin cation in NaCl aqueous solution were considered, was used to define the speciation of the systems under investigation. Measurements performed at different ionic strength va…
Use of a reduced Schiff-Base ligand to prepare novel chloro-bridged chains of rare Cu(II) trinuclear complexes with mixed azido/oxo and chloro/oxo br…
2010
Two mixed bridged one-dimensional (1D) polynuclear complexes, [Cu(3)L(2)(mu(1,1)-N(3))(2)(mu-Cl)Cl](n) (1) and {[Cu(3)L(2)(mu-Cl)(3)Cl].0.46CH(3)OH}(n) (2), have been synthesized using the tridentate reduced Schiff-base ligand HL (2-[(2-dimethylamino-ethylamino)-methyl]-phenol). The complexes have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. In both complexes the basic trinuclear angular units are joined together by weak chloro bridges to form a 1D chain. The trinuclear structure of 1 is composed of two terminal square planar [Cu(L)(mu(1,1)-N(3))] units connected by a central Cu(II) atom through bridging nitrogen atoms of end…
Exploring the redox reactivity of magnesium porphine. Insight into the origins of electropolymerisation.
2010
International audience; Magnesium(II) porphine, MgP (1), was synthesised according to the Lindsey procedure allowing to isolate and crystallise 1-formyldipyrromethane (2) as a synthetic intermediate. Unprecedented Xray diffraction studies revealed multiple intermolecular associations in the crystal between neighbouring units of 2, namely hydrogen bond and CH … π. The electrochemical behaviour of 1 was examined by means of cyclic voltammetry. In oxydation, two well-defined and distinct steps are assigned to macrocycle concerned electron transfers yielding initially the π-cation radical and π dication, respectively. The highly reactive dication condenses neutral magnesium porphine to form a d…
Reduction of ferricytochrome c catalyzed by optically active chromium(III) complexes
2009
The reduction rates of horse heart ferricytochrome c by amalgamated zinc or by electrolysis at fixed potential on a mercury pool as the cathode have been measured in a buffered solution at pH 7.5 by absorption spectrophotometry. In both cases, the reaction was strongly accelerated by the presence of the optically active complexes Lambda-[Cr(III)((S,S)-promp)H(2)O](+) (H(2)promp = N,N'-[(pyridine-2,6-diyl)bis(methylene)]-bis[(S)-proline]), Delta-[Cr(III)((R,R)-alamp)H(2)O](+) (H(2)alamp = N,N'-[(pyridine-2,6-diyl)bis(methylene)]-bis[(R)-alanine]) and Lambda-[Cr(III)((S,S)-alamp)(H(2)O)(2)](+). These were shown to undergo reversible one-electron reduction to the corresponding labile chromium(…