⁹Be and ³¹P NMR analyses on the influence of imino groups on Be²⁺ complex stabilities of a series of cyclo-μ-imido triphosphate anions.

The complexation behaviors of Be²⁺ with cyclo-μ-imido triphosphate anions, cP₃O₉-n(NH)n(3-)n= 1, 2),have been investigated by both ⁹Be and ³¹P NMR techniques at -2.3 °C in order to clarify the coordination structures of the complexes. The spectra showed that cP₃O₉n(NH)n (n = 1, 2) ligands form ML, ML₂, and M₂L complexes with Be²⁺ ions, and the formation of complexes coordinating with nitrogen atoms of the cyclic framework in the ligand molecule has been excluded.

Synthesis, protonation equilibrium and peculiar thermal decomposition behavior of cyclo-tri-μ-imidotetraphosphate.

The synthesis and isolation of the sodium salt of cyclo-tri-μ-imidotetraphosphate, i.e. Na4cP4O9(NH)3·H2O, were achieved by the hydrolysis of Na4cP4O8(NH)4·2H2O under very weak acidic conditions, i.

Stabilities of the Divalent Metal Ion Complexes of a Short-Chain Polyphosphate Anion and Its Imino Derivative.

Abstract: The stability constants of ML-type complexes of the two linear triphosphate ligand anion analogues triphosphate ([Formula: see text]) and diimidotriphosphate ([Formula: see text]) were investigated thermodynamically using potentiometric titrations according to Schwarzenbach's procedure. The stability constants of the ML-type complexes of different divalent metal ions with [Formula: see text] are larger than those of the corresponding complexes with [Formula: see text] because of the greater basicity of the imino group. The order of the stability constants for the ML-type complexes follows the Irving-Williams order, indicating that only non-bridging oxygen atoms are coordinated directly to the different metal ions in both ligands, and that the imino groups cannot participate in coordination to the metal ions.

Protonation equilibria and stepwise hydrolysis behavior of a series of thiomonophosphate anions.

The stepwise protonation constants of a series of thiomonophosphate anions, i.e., monothiomonophosphate, dithiomonophosphate, trithiomonophosphate, and tetrathiomonophosphate anions, were determined by (31)P NMR chemical shift measurements in aqueous solution.

Covalent molecular imprinting of bisphenol A using its diesters followed by the reductive cleavage with LiAlH(4).

Bisphenol A (BPA) recognition materials were synthesized by a covalent imprinting technique using BPA-dimethacrylate or BPA-diacrylate as the template monomer. Binding sites in the polymers consisted of two hydroxyl groups that are generated by reducing the ester bonds of the template monomer with lithium aluminum hydride. The polymers strongly adsorbed BPA and structurally related compounds, however, other endocrine disruptors were hardly adsorbed.

Synthetic polymers adsorbing bisphenol A and its analogues prepared by covalent molecular imprinting using bisphenol A dimethacrylate as a template molecule.

Synthetic polymers which can adsorb bisphenol A (BPA) and related compounds were prepared by a covalent molecular imprinting technique. BPA dimethacrylate, used as template molecule, was polymerized with a crosslinker, triethylene glycol dimethacrylate (TEGDMA) or trimethylol propane trimethacrylate (TRIM). After the polymerization treatment with dilute NaOH was used to cleave BPA from the polymers.

Novel strategy for molecular imprinting of phenolic compounds utilizing disulfide templates.

A molecularly imprinted polymer was synthesized by using allyl phenyl disulfide as a template. The mixture of allyl phenyl disulfide, divinylbenzene, and 2,2'-azobis(isobutyronitrile) in chloroform was polymerized by UV irradiation for 24 h at 5 degrees C and further 3 h at 80 degrees C. The disulfide bonds of the resulting polymer were reductively cleaved by NaBH(4) in methanol to give thiol groups in the binding sites.