Search results for "Acid excess"
showing 2 items of 2 documents
The determination of mineral acidity excess in solutions containing Ga(III), Al(III), Bi(III)
2002
Abstract A new procedure is proposed to carry out volumetric determinations of the strong acid content of a solution in the presence of inorganic cations such as Ga 3+ , Al 3+ , Bi 3+ which, showing in aqueous solution an acidic behaviour, introduce non negligible interferences in these determinations. Before the acid–base titration, an equivalent amount of a ligand, such as dihydrogen ethylendiamino tetraacetate is added, in order to strongly complex the cation masking it toward the successive addition of a strong base. Interferences are thus removed, and the volumetric determination of the strong acid excess plus the hydrogen ions set free from the ligand, as a consequence of the complex …
Cu2+ Coordination Properties of a 2-Pyridine Heptaamine Tripod: Characterization and Binding Mechanism
2009
The synthesis, protonation, and Cu(2+) coordination chemistry of a tripodal heptaamine ligand (L(1)) functionalized with 2-pyridine fragments at the ends of its three branches are reported. L(1) presents six relatively high protonation constants followed by much more reduced constant that as indicated by the UV-vis and NMR data, occur on the pyridine fragments. p[H]-metric, ESI/MS(+), EPR and UV-vis data show that L(1) is able to form mono-, di-, and trinuclear Cu(2+) complexes. Slippage movements and molecular reorganizations have been observed to occur as a function of p[H] in the 1:1 Cu(2+) complexes. The kinetic studies showed that the complex formation is fast and proceeds through a di…