Química Inorgànica i Orgànica: Enviaments recents
Ara mostrant els elements 681-700 de 1016
Level sets as progressing waves: an example for wake-free waves in every dimension
The potential energy surface of a molecule can be decomposed into equipotential hypersurfaces of the level sets. It is a foliation. The main result is that the contours are the wave fronts of a certain hyperbolic partial ...
Studies on Magnetic and Dielectric Properties of Antiferromagnetically Coupled Dinuclear Cu(II) in a One-Dimensional Cu(II) Coordination Polymer
A one-dimensional Cu(II) coordination polymer with encapsulated antiferromagnetically coupled binuclear Cu(II) has been synthesized by using 5-nitroisophthalic acid (5-N-IPA) and 4-aminopyridine (4-APY) [Cu2(5-N-IPA)2(4-APY)4] ...
Synthesis and properties of small interfering RNA duplexes carrying 5-ethyluridine residues
Oligoribonucleotides carrying 5-ethyluridine units were prepared using solid-phase phosphoramidite chemistry. The introduction of the tert-butyldimethylsilyl group at the 2'-OH position proceeded in good yield and very ...
Inhibition of human prolyl oligopeptidase activity by the Cyclotide Psysol 2 isolated from Psychotria solitudinum
Cyclotides are head-to-tail cyclized peptides comprising a stabilizing cystine-knot motif. To date, they are well known for their diverse bioactivities such as anti-HIV and immunosuppressive properties. Yet little is known ...
Els dendrímers o l'estètica molecular
[cat] En aquest article s'explica què s'entén per dendrímer i se subratllen els trets estructurals més característics d'aquestes noves supramolècules, les estratègies sintètiques més habituals i les maneres de funcionalitzar-les ...
Room-Temperature Spin-Dependent Transport in Metalloporphyrin-Based Supramolecular Wires
Here we present room-temperature spin-dependent charge transport measurements in single-molecule junctions made of metalloporphyrin-based supramolecular assemblies. They display large conductance switching for magnetoresistance ...
NH2- or PPh2-functionalized linkers for the immobilization of palladium on magnetite nanoparticles?
Immobilization of palladium on magnetite nanoparticles has been carried out with the assistance of two differently functionalized linkers containing phosphino-or amino-terminated groups. The linkers have been anchored to ...
Controlled heterometallic composition in linear trinuclear [LnCeLn] lanthanide molecular assemblies
The combination of two different β-diketone ligands facilitates the size-controlled assembly of pure heterometallic [LnLn′Ln] linear compounds thanks to two different coordination sites present in the molecular scaffold. ...
Trinuclear heterometallic CuII-MnII complexes of a salen type Schiff base ligand: anion dependent variation of phenoxido bridging angles and magnetic coupling
Five new trinuclear heterometallic CuII-MnII complexes [(CuL)2Mn(O2CPh)2] (1), [(CuL)2Mn(N3)2] (2), [(CuL)2Mn(NCO)2] (3), [(CuL)2Mn(NO3)2] (4) and [(CuL)2Mn(Sal)2]∙CH2Cl2 (5) have been synthesized with the di-Schiff base ...
Quantum equilibration of the double-proton transfer in a model system Porphine
There is a renewed interest in the derivation of statistical mechanics from the dynamics of closed quantum systems. A central part of this program is to understand how closed quantum systems, i.e., in the absence of a ...
Magnetic and Luminescence Properties of 8-Coordinate Holmium(III) Complexes Containing 4,4,4-Trifluoro-1-Phenyl and 1-(Naphthalen-2-yl)-1,3-Butanedionates.
A new series of mononuclear Ho3+ complexes derived from the β-diketonate anions: 4,4,4-trifluoro-1-phenyl-1,3-butanedioneate (btfa−) and 4,4,4-trifuoro-1-(naphthalen-2-yl)-1,3-butanedionate (ntfa−) have been synthesized, ...
Highly Adiabatic Time-Optimal Quantum Driving at Low Energy Cost
Time-efficient control schemes for manipulating quantum systems are of great importance in quantum technologies, where environmental forces rapidly degrade the quality of pure states over time. In this Letter, we formulate ...
Highly textured Sr, Nb, co-doped BiFeO3 thin films grown on SrRuO3/Si substrates by rf-sputtering
In this study, (011)-highly oriented Sr, Nb co-doped BiFeO3 (BFO) thin films were successfully grown on SrRuO3/Si substrates by rf-magnetron sputtering. The presence of parasite magnetic phases was ruled out based on the ...
Chiral induction in intramolecular rhodium-catalyzed [2+2+2] cycloadditions of optically active allene-ene/yne-allene substrates
Allene-yne-allene and allene-ene-allene N-tosyl-linked substrates with two chiral centres in the α-position of the allene moiety were satisfactorily prepared starting both from racemic and chiral propargylic alcohols. The ...
Entre la ciència i l'art
Sens dubte, el laboratori químic ha experimentat una gran evolució des que va néixer fins a l'actualitat. En aquest article es presenten unes breus notes d'alguns aspectes rellevants en l'evolució històrica del laboratori ...
Visionarios, videntes, visualizadores y veedores de moléculas
Si viéramos las moléculas como vemos los engranajes de un reloj, y tuviéramos la manera de manipularlas, podríamos encajar las piezas en un dispositivo molecular, igual que un experto monta un mecanismo de relojería. Los ...
Crystal size dependence of dipolar ferromagnetic order between Mn6 molecular nanomagnets
We study how crystal size influences magnetic ordering in arrays of molecular nanomagnets coupled by dipolar interactions. Compressed fluid techniques have been applied to synthesize crystals of Mn6 molecules (spin S=12) ...
Insights into Structure-Activity Relationships of Somatostatin Analogs Containing Mesitylalanine.
The non-natural amino acid mesitylalanine (2,4,6-trimethyl-L-phenylalanine; Msa) has an electron-richer and a more conformationally restricted side-chain than that of its natural phenylalanine counterpart. Taking these ...
Borane as an efficient directing group. Stereoselective 1,2-addition of organometallic reagents to borane P-stereogenic N-phosphanylimines
In non-coordinating solvents, borane was shown to be an efficient directing group for the stereoselective 1,2-addition of organolithium reagents to P-stereogenic N-phosphanylimines. Selectivity was reversed in coordinating ...
The effect of potential supramolecular-bond promoters on the DNA-interacting abilities of copper-terpyridine compounds.
Three copper(II) coordination compounds have been prepared from three different 2,2′:6′,2′′-terpyridine-based ligands, which have been selected to investigate the potential role of supramolecular interactions on the ...
