The coordination properties of the macrocyclic receptor N,N'-bis[(6-carboxy-2-pyridyl)methylene]-1,10-diaza-15-crown-5 (H(2)bp15c5) towards the lanthanide ions are reported. Thermodynamic stability constants were determined by pH-potentiometric titration at 25 °C in 0.1 M KCl. A smooth decrease in complex stability is observed upon decreasing the ionic radius of the Ln(III) ion from La [log K(L...

a series of transition metal complexes with two thiosemicarbazide schiff bases, 1-(4-dimethylaminobenzyl- idene)thiosemicarbazide (abtsc) and 1-(2-pyridincarboxyl-idene) thiosemicarbazide (tcts) were synthesized with co(ii), ni(ii), zn(ii), cd(ii) and ag(i) salts (chloride and acetate). these complexes were characterized by different methods including proton nuclear magnetic resonance (1hnmr), ...

Here, we demonstrate that a metal ion binding motif could serve as an efficient and robust tool for site-specific conjugation strategy. Cysteine-containing metal binding motifs were constructed as single repeat or tandem repeat peptides and their metal binding characteristics were investigated. The tandem repeats of the Cysteine-Glycine-Histidine (CGH) metal ion binding motif exhibited concerte...

Chapter 21 Phosphate-metal ion interactions of nucleotides and polynucleotides, by C. Klevickis and C. Grisham Sugar-metal ion interactions, by S. Yano and M. Otsuka Dichotomy of metal ion binding to N 1 and N7 of purines, by R. B. Martin General conclusions from solid state studies of nucleotide-metal ion complexes, by K. Aoki Solution structures of nucleotide-metal ion complexes. Isomeric equ...

In most aquatic systems, natural organic acids constitute an important pool of trace-metal binding ligands. The effect of natural organic matter (NOM) on metal ion sorption to mineral surfaces is a complex function of the environment in which the mineral and ions reside, as well as the source, molecular weight distribution and composition of the NOM. In spite of the well-acknowledged importance...

BACKGROUND Research interest in phosphonates metal organic frameworks (MOF) has increased extremely in the last two decades, because of theirs fascinating and complex topology and structural flexibility. In this paper we present a mathematical model for ligand/metal ion ratio of an octahedral (Oh) network of cobalt vinylphosphonate (Co(vP)·H2O). RESULTS A recurrent relationship of the ratio b...

A proton NMR method for the determination of the solvation numbers of alkaline earth cations with dimethylsulfoxide (DMSO) in nitromethane as diluent is described. The method is based on the monitoring of the resonance frequency of DMSO protons as a function of DMSO to metal ion mole ratio while keeping the metal ion concentration constant. The average solvation number of cations at any...

Nucleic acid quadruplexes are composed of guanine quartets stabilized by specific metal ions. X-ray diffraction can provide high-resolution information on the structure and metal binding properties of quadruplexes, but only if they can be crystallized. NMR can provide detailed information on the solution structure of such quadruplexes but little quantitative data concerning the metal binding si...

Electron paramagnetic resonance (EPR), Fourier transform infrared (FTIR), and solid-state 15N nuclear magnetic resonance (15N-NMR) spectroscopies were used to characterize the structure and relative strength of the interactions between metal sulfonate and amide groups in blends of lightly sulfonated polystyrene ionomers and an N-methylated polyamide, poly(N,N′-dimethylethylene sebacamide), and ...

Mesoporous heteroatom molecular sieve MCM-41 bulk crystals with the crystalline phase were synthesized via a one-step hydrothermal method using an ionic complex as template. The ionic complex template was formed by interaction between cetyltrimethylammonium ions and metal complex ion [M(EDTA)]2− (M = Co or Ni)]. The materials were characterized by X-ray diffraction, scanning electron microscopy...