Raman spectroscopy of thiosulphates

Elucidating the interfacial interactions of copper and ammonia with the sulfur passive layer during thiosulfate mediated gold leaching

“…To find spectroscopic evidence of ammonia adsorption, Figure 4 plots SHINERS spectra in the 1100 -600 cm -1 region, recorded after the addition of NH4OH to the 0.10 M Na2S2O3 electrolyte. The SHINERS spectra displays several distinct bands located at 1063, 1040, 1025, and 998 cm -1 , which correlate well with previously reported v(SO) values from polythionates with n ≥ 4, the gold-thiosulfate complex, and thiosulfate [3][4][5][6][47][48][49][50]. The weak, broad band observed between 900 -750 cm -1 which remains fairly consistent after the addition of ammonia may be associated with oxide formation, e.g.…”

Frustration vs Prenucleation: Understanding the Surprising Stability of Supersaturated Sodium Thiosulfate Solutions

“…They feature vibrational peaks above 10 THz, librational bands around 2 THz, as well as the α-relaxation band below 100 GHz, and the β-relaxation band between the librations and the α-relaxation. The positions of the vibrational bands at 10.2, 13.4, and 16.2 THz (306, 402, and 488 cm –1 ) have been shown to be concentration-independent, , and no significant temperature dependence was observed here in the 1:5 solution spectra. On the other side of the frequency scale, the α-relaxation band shows a shift toward lower frequencies with decreasing temperature.…”

Active site of the solvated thiosulfate ion characterized by hydration structures and dynamics

“…6a shows the isolated spectra of the ν s (SO 3 ) and ν as (SO 3 ) modes, corresponding to the characteristic assignment in the Raman experiment. 31 The spectra in Fig. 6b and 6c present the mixing of the ν(SS) with δ s (SO 3 ) modes and the δ as (SO 3 ) with δ(SS) modes, respectively, corresponding to the normal coordinate analysis of the Raman spectra by Alvarez et al 30 The splitting of the ν(SS) peak is in accordance with the susceptibility of changing the length of the S-S bond with the dynamics of water molecules within its hydration sphere, similar to the ν(SH) spectrum of the sulfonate ion.…”

“…[18][19][20][21][22][23][24][25][26][27][28] The calculated spectra of the normal modes for the thiosulfate ion are one of the dynamical properties comparable with the assignment in the Raman spectra obtained from sodium or ammonium thiosulfate in aqueous solutions. 10,[29][30][31] Although the thiosulfate ion is a common ion in aqueous solutions, there are few experimental and theoretical investigations on the hydration properties of this ion. To our knowledge, there is only an experiment consisting of the measurement of ultrasonic velocities as the functions of concentration and temperature to estimate the hydration number of aqueous sodium thiosulfate.…”