New Polypodal Polycarboxylic Ligands − Complexation of Rare-Earth Ions in Aqueous Solution

Abstract

The complexation ability of new polypodal carboxylic ligands prepared from 2,2-bis(hydroxymethyl)-1-alkanols was investigated in aqueous solution with Y 3+ and various lanthanide ions (La 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Tb 3+ , Dy 3+ ). The values of the stability constants for ML complexes are of the order of 10 4 for the hexadentate trioxypropionates, 10 7 for the

Improving the accuracy of Cu(ii)–nitroxide RIDME in the presence of orientation correlation in water-soluble Cu(ii)–nitroxide rulers

“…A further design criterion was that the ligand, which is needed for anchoring the metal ion, forms stable complexes with several metal ions of importance for metal ion-nitroxide EPR spectroscopy. [17][18][19][20][21][22]43,46,49,[84][85][86][87][88][89][90][91] To reach these goals the rod-like spacer was furnished with highly hydrophilic, branched oligo(ethyleneglycol) (PEG) chains and the ligands PyMTA 66,92,93 and TAHA 83,92,94 were selected (Fig. 1).…”

“…To ease the separation of the target compound from the accompanying oxidative alkyne dimerization product the polar tagging strategy [98][99][100] was applied. Reaction of the amino functionalised spacer 4 with the N-acylpyridinium salt 6, which was preformed but not isolated, 101 83 The protonation degree at pH 7 given with the formula of PyMTA-nitroxide 19 is based on the data for diethylenetriaminepentaacetic acid (DTPA) which is structurally similar to PyMTA. 51 gave the spacer-nitroxide conjugate 7.…”

Cys-Ph-TAHA: a lanthanide binding tag for RDC and PCS enhanced protein NMR

“…This C 3 -symmetric ligand offers nine coordination sites and forms stable complexes with lanthanide ions (e.g. log K = 14.85 for Dy 3+ at pH 7, Viguier et al 2001). As was determined by dysprosium induced shift measurements (Alpoim et al 1992), less than 1.4 water molecules are located within the inner coordination sphere at pH 7.

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Tuneable energy barriers in tetrairon(III) single-molecule magnets

“…The reaction of 1 with a tripodal ligand such as H 3 L ¼ R-CðCH 2 OHÞ 3 [3,4] in a MeOH=Et 2 O solvent mixture Eq. (2) affords the compounds Fe 4 ðLÞ 2 ðdpmÞ 6 ð2Þ:…”