Speciation and the structure of lead(ii) in hyper-alkaline aqueous solution

Abstract

In hyper-alkaline aqueous solutions, lead(ii) is present exclusively as [Pb(OH)3]−. Other species, like [Pb(OH)4]2−, [PbOOH]−or [PbO2]2−are not detectable.

Fabrication of a Reusable Carbon Dot/Gold Nanoparticle/Metal–Organic Framework Film for Fluorescence Detection of Lead Ions in Water

“…At alkaline pH, dissociation of thiols favors thiolates, which could lead to increased quenching. However, the alkaline condition would cause the formation of lead hydroxides such as [Pb­(OH)] + , Pb­(OH) 2 , and complexes that reduce the availability of free Pb 2+ to quench the fluorescence of the HS-C/Au(1.4)/UiO-66 film. At the acidic pH, thiolate formation from the dissociation of the −SH group is not favored, hence the quenching response of the HS-C/Au(1.4)/UiO-66 film is lower than at pH 7.…”

On solvated tin(iv) ions and the coordination chemistry of high-valent d10 metal ions

“…The coordination chemistry of tin(II) and lead(II) is strongly affected by occupied anti-bonding orbitals causing large voids, so-called gaps, in their coordination spheres. [3][4][5][6] This is not the case for the tetravalent ions, but for neither tin(IV) nor lead(IV), no hydrate or solvate structures have previously been reported. We have made several attempts to prepare aqueous solutions of hydrated tin(IV) ions in strongly acidic solution, but it always resulted in precipitation of solid tin(IV) oxide, SnO 2 .…”

“…hyd./sol. 1.957 [11] 2.130 [9] 2.229 [5] n/a n/a n/a Tables S4 and S5 OH − 1.973 [7] 2.160 [2] 2.257 [1] 1.905 [5] 2.049 [20] 2.158 [4] Tables S1, S4 and S5 r M n+ 0.617 0.790 0.889 n/a n/a n/a 24 r M n+ Sh.…”

Sorption mechanisms of Chromium(III), Copper(II) and Lead(II) on two natural mixed clays from Burkina Faso as determined by extended X-ray absorption fine structure (EXAFS) spectroscopy

“…Chromium(III) is adsorbed as hydrolysed tetrameric complexes at both acidic and basic pH values, one chromium in the hydrolyzed tetramer binds to the surface through two oxygens to one or two Fe 3+ ions in the mineral surface. aqueous solution (Bajnóczi et al, 2014). Copper(III) is hydrolyzed to a polymeric complex or precipitateadsorbed to the clay surface.…”