Search results for "CERAMICS"
showing 10 items of 1599 documents
Cu2+-Induced formation of cage-like compounds containing pyrazole macrocycles
2002
The crystal structure of the complex [Cu4(H22L)2(H2O)2- (ClO4)2](ClO4)2·2H2O where L is a new pyrazole ligand containing 1,5-diaminopentane spacers represents a new form of obtaining metal ion-induced inorganic–organic cages. Escarti Alemany, Francisco, franesa@alumni.uv.es ; Latorre Saborit, Julio, Julio.Latorre@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es
Binuclear Cu2+ complex mediated discrimination between L-glutamate and L-aspartate in water.
2005
L-Glutamate and L-aspartate selectivity is achieved by the action of two Cu2+ metal ions rightly disposed in a cyclophanetype macrocyclic framework; electrochemical sensing of glutamate has been achieved by adsorption of the copper complexes on graphite electrodes. Verdejo Viu, Begoña, Begona.Verdejo@uv.es ; Domenech Carbo, Antonio, Antonio.Domenech@uv.es ; Jimenez Garcia, Hermas Rafael, Hermas.Jimenez@uv.es ; Soriano Soto, Concepción, Concepcion.Soriano@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es
Versatile synthesis of cationic N-heterocyclic carbene–gold(i) complexes containing a second ancillary ligand. Design of heterobimetallic ruthenium–g…
2016
We describe a versatile and quick route to cationic gold(i) complexes containing N-heterocyclic carbenes and a second ancillary ligand (such as phosphanes, phosphites, arsines and amines) of interest for the synthesis of compounds with potential catalytic and medicinal applications. The general synthetic strategy has been applied in the preparation of novel cationic heterobimetallic ruthenium(ii)-gold(i) complexes that are highly cytotoxic to renal cancer Caki-1 and colon cancer HCT 116 cell lines while showing a synergistic effect and being more selective than their monometallic counterparts.
A family of heterometallic wheels containing potentially fourteen hundred siblings
2005
The synthesis and structure of new heterometallic wheels are reported, with preliminary studies of selected compounds.
endo-Functionalized molecular tubes : selective encapsulation of neutral molecules in non-polar media
2016
Four endo-functionalized molecular tubes with urea/thiourea groups in the deep cavities have been synthesized, and their binding ability to neutral molecules studied. Very high binding affinity and selectivity have been achieved, which are rationalized by invoking the shape and electrostatic complementarity and dipole alignment.
Glassy behavior of molecular crystals: A comparison between results from MD-simulation and mode coupling theory
2005
We have investigated the glassy behavior of a molecular crystal built up with chloroadamantane molecules. For a simple model of this molecule and a rigid fcc lattice a MD simulation was performed from which we obtained the dynamical orientational correlators $S_{\lambda \lambda '}({\bf{q}},t)$ and the ``self'' correlators $S_{\lambda \lambda '}^{(s)}(t)$, with $\lambda = (\ell, m)$, $\lambda' = (\ell', m')$. Our investigations are for the diagonal correlators $\lambda = \lambda'$. Since the lattice constant decreases with decreasing temperature which leads to an increase of the steric hindrance of the molecules, we find a strong slowing down of the relaxation. It has a high sensitivity on $…
Icosahedral carboranes as scaffolds for congested regioselective polyaryl compounds: the distinct distance tuning of C–C and its antipodal B–B
2019
Four-fold aryl substituted o-carborane derivatives with defined patterns of substitution at the antipodal region of the cluster carbon atoms have been achieved. It is proven that this region is congested but lacks steric hindrance. Also, the two antipodal sites Cc–Cc and B9–B12 are affected very distinctly by electron donor substituents.
Evidence that steric factors modulate reactivity of tautomeric iron-oxo species in stereospecific alkane C-H hydroxylation
2014
A new iron complex mediates stereospecific hydroxylation of alkyl C-H bonds with hydrogen peroxide, exhibiting excellent efficiency. Isotope labelling studies provide evidence that the relative reactivity of tautomerically related oxo-iron species responsible for the C-H hydroxylation reaction is dominated by steric factors This work has been supported by the European Union (the Erasmus Mundus program), the International Research Training Group Metal Sites in Biomolecules: Structures, Regulation and Mechanisms (www.biometals.eu), and COST Action CM1003. M.C. acknowledges ERC-29910, MINECO of Spain for CTQ2012- 37420-C02-01/BQU and CSD2010-00065, catalan DIUE (2009SGR637) and an ICREA academ…
Steric vs. electronic stereocontrol in syndio- or iso-selective ROP of functional chiral β-lactones mediated by achiral yttrium-bisphenolate complexes
2018
International audience; Origins of stereoselectivity in ROP of racemic chiral cyclic esters promoted by achiral yttrium complexes, resulting in the formation of highly heterotactic polylactide, and highly syndiotactic or, more uniquely, highly isotactic poly(3-hydroxybutyrate)s, are discussed. A close interplay between the nature of the cyclic ester, most particularly of the exocyclic functional chain installed on the chiral center of β-lactones, and the ortho-substituents installed on the phenolate rings of the ligand, results in various determining secondary interactions of steric and also electronic nature.
Ligand effects on the dimensionality of oxamato-bridged mixed-metal open-framework magnets
2012
Increasing dimensionality [from 2D (1) to 3D (2)] and T(C) [from 10 (1) to 20 K (2)] in two new oxamato-bridged heterobimetallic Mn(II)(2)Cu(II)(3) open-frameworks result from the steric hindrance provided by the different alkyl substituents of the N-phenyloxamate bridging ligands.