Search results for "complex"
showing 10 items of 5889 documents
A giant hybrid organic-inorganic octahedron from a narrow rim carboxylate calixarene.
2020
Here we discovered an unprecedented giant octahedral coordination compound bearing 16 Zn2+, 12 Na+, 8 O2-, 4 OH-, 13 H2O and 6 L4- ligands [L4- = fully deprotonated tetra(carboxymethoxy)calix[4]arene]. Its structure was elucidated by single-crystal X-ray diffraction, wavelength-dispersive X-ray spectroscopy and MALDI-TOF mass spectrometry. This compound, Zn8Na6L6⊃Zn8Na6O8(OH)4(H2O)13 (external⊃internal), has eight tetrahedral zinc ions forming the coordination vertices of an outermost cube where carboxylate groups from the sodium calixarenes are anchored. Its core consists of eight Zn2+, six Na+, eight O2-, and four OH- distributed over three layers, besides thirteen coordinated H2O molecul…
Tuning antiviral CD8 T-cell response via proline-altered peptide ligand vaccination
2019
AbstractViral escape from CD8+cytotoxic T lymphocyte responses correlates with disease progression and represents a significant challenge for vaccination. Here, we demonstrate that CD8+T cell recognition of the naturally occurring MHC-I-restricted LCMV-associated immune escape variant Y4F is restored following vaccination with a proline-altered peptide ligand (APL). The APL increases MHC/peptide (pMHC) complex stability, rigidifies the peptide and facilitates T cell receptor (TCR) recognition through reduced entropy costs. Structural analyses of pMHC complexes before and after TCR binding, combined with biophysical analyses, revealed that although the TCR binds similarly to all complexes, t…
The Influence of Biomass Ash on the Migration of Heavy Metals in the Flooded Soil Profile - Model Experiment
2014
Soils that have been exposed to fl ood waters can be heavily polluted by inorganic and organic compounds. They are mainly compounds which appear in dissolved or suspended form fl owing together with heavily laden fl oodwater, as well as compounds created as a result of reactions in the soil profi le, mostly due to anaerobic transformation of organic matter. Heavy metals brought with fl ood waters are absorbed by the soil and also washed out from fl ood sediments by precipitation when the fl ood recedes. This paper presents the results of research on the effects of fertilization with ash from incineration or pyrolysis of biomass on the migration process of heavy metals (Zn, Cu, Cr, Ni, Pb, C…
Hydrophilic and hydrophobic copolymers of a polyasparthylhydrazide bearing positive charges as vector for gene therapy
2008
BACKGROUND: The design of polymeric vectors for gene delivery provided with specific properties is one of the most critical aspects for a successful gene therapy. These polymers should be biocompatible as well as able to carry efficiently DNA to target tissues and to transfect it into cells. RESULTS: The formation of complexes of poly[(α,β-asparthylhydrazide)–poly(ethylene glycol)] and poly[(α,β-asparthylhydrazide)–hexadecylamine] copolymers functionalised with glycidyltrimethylammonium chloride (PAHy–PEG-GTA and PAHy–C16-GTA, respectively) with DNA was studied. The effects of the introduction of hydrophilic (PEG) or hydrophobic (C16) moieties on the chains of PAHy–GTA copolymers, such as t…
ChemInform Abstract: Oxamato-Based Coordination Polymers: Recent Advances in Multifunctional Magnetic Materials
2014
The design and synthesis of novel examples of multifunctional magnetic materials based on the so-called coordination polymers (CPs) have become very attractive for chemists and physicists due to their potential applications in nanoscience and nanotechnology. However, their preparation is still an experimental challenge, which requires a deep knowledge of coordination chemistry and large skills in organic chemistry. The recent advances in this field using a molecular-programmed approach based on rational self-assembly methods which fully exploit the versatility of the coordination chemistry of the barely explored and evergreen family of N-substituted aromatic oligo(oxamato) ligands are prese…
FTIR TENTATIVE CHARACTERIZATION OF HUMIC ACIDS EXTRACTED FROM ORGANIC MATERIALS
2001
Turkish humic acids, extracted from different materials, were characterized by their infrared spectra and by means of acidity measurements. The information obtained is of great interest to ascertain the nature and origin of humic acid samples.
Equilibrium solution coordination chemistry
2018
Welcome to this themed issue of New Journal of Chemistry entitled “Equilibrium Solution Coordination Chemistry”.