The atom transfer radical polymerization of styrene using activators generated by electron transfer (AGET ATRP) has been carried out in bulk in a limited amount of air at 110 °C, using 1,3,5‐(2′‐bromo‐2′‐methylpropionato)benzene (BMPB) as an initiator and FeCl3 · 6H2O/tris(3,6‐dioxaheptyl) amine (TDA‐1)/ascorbic acid (VC) as a novel FeIII‐mediated catalyst system. The results of the polymerizations demonstrate the features of ‘living’/controlled free‐radical polymerization, such as the number‐average molecular weights being close to their corresponding theoretical values and increasing linearly with monomer conversion, and narrow molecular weight distributions ( = 1.18–1.26). The end functionality of the obtained polymers was confirmed by 1H and 13C NMR spectra as well as a chain‐extension reaction.
Metallo‐supramolecular chemistry offers possibilities for the construction of stimuli‐responsive polymeric materials where the environment can have a large impact on the reversibility and strength of interactions between the individual components. The potential of manipulating the strength of the intermolecular non‐covalent bonds can result in impressive modifications of the metallo‐supramolecular structure and, subsequently, produces changes in the properties of the designed material. The present feature article provides an overview on recent developments in the field of metallo‐polymerization of chelating terpyridyl and analogues ligands. Synthetic strategies are described followed by a discussion regarding the characterization and the application of the reviewed metallo‐supramolecular structures, mainly based on terpyridines.
The RPdIn compounds (R = rare earth) crystallise in the hexagonal ZrNiAl-type crystal structure. The compounds from this family exhibit a great variety of interesting magnetic properties including heavy fermion behaviour. In order to get a deeper insight into nature of magnetism of RPdIn with light rare earths elements (La–Nd) an inelastic neutron scattering experiment was performed. For compounds with Pr and Nd excitations due to crystal field were clearly distinguished. On the other hand, interesting behaviour for the CePdIn sample was observed. The sample exhibits no signs of crystal field excitations, likely due to highly delocalised Ce 4f states leading to its heavy fermion behaviour. 相似文献
Introduction In the past decade, the imino-complexes based on late transition metal have received significantly increasing attention for their excellent performance in the olefin polymerization area since Brookhart et al.[1-8] 相似文献
Introduction The design and syntheses of multidentate N-donor ligands have become the focus of much inter-est in the chemical field[1-4]because these ligands can form multinuclear metalxompounds, coordina-tion polymers and supramolecular compounds,which play a very important role in the bilolgicalsystems, magnetic materials,electric materials,optical materials and otherfields[5-8]. 相似文献
The reaction of [M(H2L)2] [M = Ni(II) Cu(II)] (K+H2L− = N-(pyridine-4-carbonyl)-hydrazine carbodithioate) with excess of ethylenediamine (en) gave mixed ligand complexes [Ni(en)2(4-pytone)2] (4-pytone = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione), and [Cu(en)2](4-pytol)2·H2O (4-pytol = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol). The metal complexes have been characterized with the aid of elemental analyses, IR, magnetic susceptibility and single crystal X-ray studies. Complexes (1) and (2) crystallize in monoclinic system, space group P1 21/n1 and C2/c, respectively. The ligand after cyclization is present in the deprotonated thiol form in the Cu(II) complex where it is ionically bonded through sulfur. In the Ni(II) complex (1) bonding of the ligand take place through oxadiazole nitrogen and the ligand exists as the thione form. 相似文献
Nucleolytic activities of some new oxime-type ligand complexes were investigated by neutral agarose gel electrophoresis. Analysis
of the cleavage products in agarose gel indicated that all complexes used converted supercoiled pUC18 plasmid DNA to its nicked
or linear form. It was found that nucleolytic activities of the complexes depend on the complex concentration, reaction time
and the presence of a cooxidant (magnesium monoperoxyphthalate, MMPP) in the reaction mixture. However, the complexes cleaved
pUC18 plasmid DNA at all investigated pH values. Nucleolytic activities of complexes were investigated for different complex
concentrations (0.1–100 μmol L−1), pH values (6.0–10.0) and reaction times (0–60 min). Molecular modeling studies performed by the Hyperchem Software together
with DNA-binding studies showed that planar sites of the complexes intercalated into double stranded DNA. It can be concluded
that all oxime-type ligand complexes used can be evaluated as nuclease mimics. 相似文献
