Search results for "Chelates"
showing 4 items of 4 documents
The [Pd(bipy)]2+ “merry-go-round”: Insights into the lability of the Pd–N bond
2009
Abstract Two tripods (1 and 2) featuring pyrimidinyl pendant arms have been synthesized from 5-(1H-pyrazol-3-yl)-pyrimidine (5) and 1,3,5-tribromomethylbenzene derivatives. Reaction with three equivalents of [Pd(bipy)](NO3)2 to form a macrotricycle closed by palladium coordination unexpectedly afforded the mononuclear species [Pd(1)(bipy)]2+ and [Pd(2)(bipy)]2+. These complexes show fluxional behavior on the 1H NMR timescale, the [Pd(bipy)]2+ fragment hopping between the pyrimidinyl coordinating moieties. The ΔGc‡’s estimated by the coalescence method are temperature independent, which means that ΔSc‡ = 0. This indicates that the “merry-go-round” process of [Pd(bipy)]2+ occurs intramolecula…
Gadolinium-chelating nanogels as MR contrast agesnts specifically targeting tumor cells
2014
Development of multifunctional nanogels coordinating paramagnetic ions and displacing targeting ligands for preferential accumulation into tumors. Low molecular-weight Gd-chelates are widely used in clinical MRI for various purposes. However, these contrast agents (CAs) have several shortcomings: they rapidly extravasate from blood vessels to the interstitial space, have a short circulation times and show poor contrast at high magnetic fields. Incorporating gadolinium into flexible nanogels has the potential of increasing intravascular half-life, accumulation and retention in specific body compartments of the CA as well as increasing the MR signal, since many metal ions can be coordinated t…
Changes of several metabolic parameters of soya inoculated with phytopathogens at application nanochelates
2022
n greenhouse experiments changes in several metabolic parameters soybeans plants after inoculation by P. savastanoi pv. glycinea 9190, X. axonopodis pv. glycines 9192, BCMV, A. laidlawii on background pre-treatment by nanochelates (NHs) of V, Ge, Cu, Mo have been shown. The phenolic compounds content increased in leaves at inoculation by phytopathogens on background pre-treatment by NHs and without it. The content of H2O2 in leaves increased in variants: BCMV (+VNHs, GeNHs, CuNHs), 9192 (+VNHs, CuNHs), 9190 (+GeNHs, CuNHs), A. laidlawii+MoNHs. But it decreased in the variants: BCMV + MoNHs, A. laidlawii + VNHs, 9190 + VNHs, 9192 (+ GeNHs, CuNHs) compared to controls. The peroxidase activity…
Approaching ‘kit-type’ labelling with 68Ga : the DATA chelators.
2015
The DATA chelators are a novel class of tri-anionic ligands based on 6-amino-1,4-diazepine-triacetic acid, which have been introduced recently for the chelation of (68)Ga. Compared with macrocyclic chelators based on the cyclen scaffold (i.e., DOTA, DO3A, and DO2A derivatives), DATA chelators undergo quantitative radiolabelling more rapidly and under milder conditions. In this study, a systematic evaluation of the labelling of four DATA chelators--DATA(M), DATA(P), DATA(Ph), and DATA(PPh)--with (68)Ga is presented. The results highlight the extraordinary potential of this new class of chelators for application in molecular imaging using (68)Ga positron emission tomography (PET).