Search results for "Chela"
showing 10 items of 415 documents
Efficient Synthesis of 1,4,7-Triazacyclononane and 1,4,7-Triazacyclononane-Based Bifunctional Chelators for Bioconjugation (Eur. J. Org. Chem. 35/201…
2014
Efficient Synthesis of 1,4,7-Triazacyclononane and 1,4,7-Triazacyclononane-Based Bifunctional Chelators for Bioconjugation
2014
The reaction of diethylenetriamine with chloroacetaldehyde yielded a bicyclic aminal intermediate for the synthesis of 1,4,7-triazacyclononane (TACN), a macrocyclic polyamine the derivatives of which find applications as catalysts, bleaching agents, and chelators for medical imaging. This new synthetic protocol outperforms the synthetic methods described so far because it does not involve any cyclization step. Moreover, this aminal intermediate allowed access to a new family of TACN derivatives functionalized on the carbon skeleton, for example, C-aminomethyl-TACN. This novel compound is a precursor of valuable bifunctional chelating agents for nuclear medicine, in particular, for the prepa…
Selectively Functionalized Constrained Polyazamacrocycles: Building Blocks for Multifunctional Chelating Agents
2013
A new class of cross-bridged and side-bridged 1,4,7,10-tetraazacyclotridecanes (homocyclens) bearing an aminomethyl pendant arm on the carbon skeleton has been prepared. The regioselectivity of the quaternization of the bis-aminal intermediates is discussed on the basis of X-ray diffraction and NMR experiments. These new polyazamacrocycles are valuable precursors of bifunctional chelating agents for applications in nuclear medicine.
{1,1′-Bis[bis(5-methyl-2-furyl)phosphino]ferrocene-κ2P,P′}dichloroplatinum(II) dichloromethane hemisolvate
2005
The synthesis of the title compound, [FePtCl2(C15H14O2P)2]·0.5CH2Cl2, has been achieved by reacting PtCl2(PhCN)2 with the 1,1′-bis[bis(5-methyl-2-furyl)phosphino]ferrocene chelating ligand. The environment at the Pt atom can be described as distorted square-planar, with two cis-Cl atoms and two cis-P atoms.
Nickel as a Lewis Base in a T‐Shaped Nickel(0) Germylene Complex Incorporating a Flexible Bis(NHC) Ligand
2018
Flexible, chelating bis(NHC) ligand 2, able to accommodate both cis- and trans-coordination modes, was used to synthesize (2)Ni(η 2 -cod), 3. In reaction with GeCl2, this produced (2)NiGeCl2, 4, featuring a T-shaped Ni(0) and a pyramidal Ge center. Complex 4 could also be prepared from [(2)GeCl]Cl, 5, and Ni(cod)2, in a reaction that formally involved Ni-Ge transmetalation, followed by coordination of the extruded GeCl2 moiety to Ni. A computational analysis showed that 4 possesses considerable multiconfigurational character and the Ni→Ge bond is formed through σ-donation from the Ni 4s, 4p, and 3d orbitals to Ge. (NHC)2Ni(cod) complexes 9 and 10, as well as (NHC)2GeCl2 derivative 11, incor…
Maturation of a Key Resource – The Germanium-68/Gallium-68 Generator: Development and New Insights
2011
(68)Ge/(68)Ga radionuclide generators have been investigated for almost fifty years, since the cyclotron-independent availability of positron emitting (68)Ga via the (68)Ge/(68)Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally reach a level of (68)Ge/(68)Ga radionuclide generator designs adequate to the modern requirements of radiometal labelling chemistry. Nevertheless, most of the existing commercial generator systems address aspects of (68)Ge breakthrough and safe synthesis of (68)Ga radiopharmaceuticals by adopting eluate post-processing …
Imidotungsten(VI) complexes with chelating phenols as ROMP catalysts
2011
Abstract Tungsten(VI) complexes of the type [W(NPh)Cl3(L)] (L = chelating phenolate) were studied as catalyst precursors for ROMP of 2-norbornene, dicyclopentadiene and 5-vinyl-2-norbornene. These compounds form active catalysts when treated by ethyl magnesium bromide. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atmosphere techniques. Synthesis and crystal structure of a new precursor complex [W(NPh)Cl3(LS)] (LS = 2,4-di-tert-butyl-6-(phenylthiomethyl)phenolate) are also described.
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2012
International audience
Dibromido[N-(1-diethylamino-1-oxo-3-phenylpropan-2-yl)-N′-(pyridin-2-yl)imidazol-2-ylidene]palladium(II) dichloromethane monosolvate
2019
In the molecule of the title N,N′-disubstituted imidazol-2-ylidene palladium(II) complex, [PdBr2(C21H24N4O)]·CH2Cl2, the palladium(II) atom adopts a slightly distorted square-planar coordination (r.m.s. deviation = 0.0145 Å), and the five-membered chelate ring is almost planar [maximum displacement = 0.015 (8) Å]. The molecular conformation is enforced by intramolecular C—H...Br hydrogen bonds. In the crystal, complex molecules and dichloromethane molecules are linked into a three-dimensional network by C—H...O and C—H...Br hydrogen bonds.
Crystal structure of bis(2-methyl-1H-imidazol-3-ium) dihydroxidobis(oxalato-κ2 O 1,O 2)stannate(IV) monohydrate
2016
The SnIV atom in the anion of the title compound is six-coordinated by two OH groups and four O atoms from two chelating oxalate ligands. Several N—H⋯O and O—H⋯O hydrogen bonds involving the stannate dianions, the cations and the water molecules result into a three-dimensional network structure.