Protonation of imines by water in the presence of salts: role of cooperative effects in water-shared ion-pairs

1990 ◽  
Vol 94 (17) ◽  
pp. 6908-6911 ◽  
Author(s):  
J. Corset ◽  
F. Froment
Keyword(s):  
Ion Pairs ◽  
Cooperative Effects

The effect of the trisulfur radical ion on molybdenum transport by hydrothermal fluids

2021 ◽  
Author(s):  
Maria A. Kokh ◽  
Clement Laskar ◽  
Gleb S. Pokrovski
Keyword(s):  
Composition Range ◽  
Ion Pairs ◽  
Primary Source ◽  
Econ Geol ◽  
Hydrothermal Conditions ◽  
Earth Planet ◽  
Porphyry Deposits ◽  
Experimental And Theoretical Studies ◽  
Partitioning Behavior

<p>Knowledge of molybdenum (Mo) speciation under hydrothermal conditions is a key for understanding the formation of porphyry deposits which are the primary source of Mo. Existing experimental and theoretical studies have revealed a complex speciation, solubility and partitioning behavior of Mo in fluid-vapor-melt systems, depending on conditions, with the (hydrogen)molybdate (HMoO<sub>4</sub><sup>-</sup>, MoO<sub>4</sub><sup>2-</sup>) ions and their ion pairs with alkalis in S and Cl-poor fluids [1-3], mixed oxy-chloride species in strongly acidic saline fluids [4, 5], and (hydrogen)sulfide complexes (especially, MoS<sub>4</sub><sup>2-</sup>) in reduced H<sub>2</sub>S-bearing fluids and vapors [6-8]. However, these available data yet remain discrepant and are unable to account for the observed massive transport of Mo in porphyry-related fluids revealed by fluid inclusion analyses demonstrating 100s ppm of Mo (e.g., [9]). A potential missing ligand for Mo may be the recently discovered trisulfur radical ion (S<sub>3</sub><sup>•-</sup>), which is predicted to be abundant in sulfate-sulfide rich acidic-to-neutral porphyry-like fluids [10]. We performed exploratory experiments of MoS<sub>2</sub> solubility in model sulfate-sulfide-S<sub>3</sub><sup>•-</sup>-bearing aqueous solutions at 300°C and 450 bar. We demonstrate that Mo can be efficiently transported by S<sub>3</sub><sup>•-</sup>-bearing fluids at concentrations ranging from several 10s ppm to 100s ppm, depending on the fluid pH and redox, whereas the available data on OH-Cl-S complexes cited above predict negligibly small (<100 ppb) Mo concentrations at our conditions. Work is in progress to extend the experiments to wider T-P-composition range of porphyry fluids and to quantitatively assess the role of S<sub>3</sub><sup>•-</sup> in Mo transport by geological fluids.</p><ul><li>1. Kudrin A.V. (1989) <em>Geochem. Int. </em><strong>26</strong>, 87–99.</li> <li>2. Minubayeva Z. and Seward T.M. (2010) <em>Geochim. Cosmochim. Acta</em> <strong>74</strong>, 4365–4374.</li> <li>3. Shang L.B. et al. (2020) <em>Econ. Geol. </em><strong>115</strong>, 661–669.</li> <li>4. Ulrich T. and Mavrogenes J. (2008) <em>Geochim. Cosmochim. Acta </em><strong>72</strong>, 2316-2330.</li> <li>5. Borg S. et al. (2012) <em>Geochim. Cosmochim. Acta</em> <strong>92</strong>, 292–307.</li> <li>6. Zhang L. et al. (2012) <em>Geochim. Cosmochim. Acta</em> <strong>77</strong>, 175–185.</li> <li>7. Kokh M.A. et al. (2016) <em>Geochim. Cosmochim. Acta </em><strong>187</strong>, 311–333.</li> <li>8. Liu W. et al. (2020) <em>Geochim. Cosmochim. Acta</em> <strong>290</strong>, 162–179.</li> <li>9. Kouzmanov K. and Pokrovski G.S. (2012) <em>Soc. Econ. Geol. Spec. Pub.</em> <strong>16</strong>, 573–618.</li> <li>10. Pokrovski G.S. and Dubessy J. (2015) <em>Earth Planet. Sci. Lett. </em><strong>411</strong>, 298–309.</li> </ul>

scholarly journals Contact Ion Pairs on a Protonated Azamacrocycle: the Role of the Anion Basicity

2016 ◽  
Vol 27 (4) ◽  
pp. 615-621 ◽  
Author(s):  
Caterina Fraschetti ◽  
Antonello Filippi ◽  
Maria Elisa Crestoni ◽  
Enrico Marcantoni ◽  
Marco Glucini ◽  
...  
Keyword(s):  
Ion Pairs ◽  
Contact Ion Pairs

The role of ion pairs and ion activity in classification of ground waters for irrigation in Erbil plain

2013 ◽  
Vol 16 (special) ◽  
pp. 177-188
Author(s):  
Akram. O. Esmail ◽  
◽  
Hemn.O. Salih ◽  
Keyword(s):  
Ion Pairs ◽  
Ground Waters ◽  
Ion Activity

Cooperative effects of inorganic and organic structure-directing agents in ZSM-5 crystallization

2018 ◽  
Vol 3 (1) ◽  
pp. 159-170 ◽  
Author(s):  
Aseem Chawla ◽  
Rui Li ◽  
Rishabh Jain ◽  
R. John Clark ◽  
James G. Sutjianto ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Molecular Modelling ◽  
Synergistic Effects ◽  
Cooperative Effects ◽  
Bulk Crystallization ◽  
Organic Structure ◽  
Structure Directing Agents ◽  
Inorganic And Organic

A combination of bulk crystallization studies and molecular modelling are used to elucidate the role of dual inorganic/organic SDAs in ZSM-5 synthesis. Our findings reveal unexpected synergistic effects on crystallization times and physicochemical properties.

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