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The Hydrosphere and Water Chemistry
Published in Stanley E. Manahan, Environmental Chemistry, 2022
This section discusses some of the fundamentals of complexation in water. A complex consists of a central metal atom to which neutral or negatively charged ligands possessing electron-donor properties are bonded. The complex may be neutral or may have a positive or negative charge. The ligands are contained within the coordination sphere of the central metal atom. Depending on the type of bonding involved, the ligands within the coordination sphere are held in a definite structural pattern. However, in solution, ligands of many complexes may exchange rapidly between solution and the coordination sphere of the central metal ion.
Chemical Equilibrium
Published in Armen S. Casparian, Gergely Sirokman, Ann O. Omollo, Rapid Review of Chemistry for the Life Sciences and Engineering, 2021
Armen S. Casparian, Gergely Sirokman, Ann O. Omollo
The region surrounding the central atom or ion and its ligands is called the coordination sphere. The coordination number is the total number of points at which the central atom or ion attaches to its ligands. Both [Co(NH3)6]3+ and [CoCl(NH3)5]2+ have coordination numbers of 6. The most common coordination numbers observed in complex ions are 2, 4, and 6. If the complex carries a net electric charge, as the two examples given here do, it is called a complex ion. If it is electrically neutral, it is referred to as a coordination compound. An example of a coordination compound is [Co(NH3)6]Cl3.
The Hydrosphere and Water Chemistry
Published in Stanley Manahan, Environmental Chemistry, 2017
This section discusses some of the fundamentals of complexation in water. A complex consists of a central metal atom to which neutral or negatively charged ligands possessing electron-donor properties are bonded. The complex may be neutral or may have a positive or negative charge. The ligands are contained within the coordination sphere of the central metal atom. Depending on the type of bonding involved, the ligands within the coordination sphere are held in a definite structural pattern. However, in solution, ligands of many complexes exchange rapidly between solution and the coordination sphere of the central metal ion.
A Review on the Application of Quaternary Ammonium-Based Ionic Liquids in Mineral Flotation
Published in Mineral Processing and Extractive Metallurgy Review, 2020
Hrushikesh Sahoo, Swagat S. Rath, Bisweswar Das
A wide range of both inorganic and organic reagents are used in industries for flotation to recover the fine particles from the ores. The reagents used in flotation study can be classified as collector, frother, activator, depressant, dispersant, modifier, etc. Among all these parameters, the collector has the highest impact on the flotation process. Thiols, alkyl carboxylates, sulfates, sulfonates, phosphates, amines, alkylphosphonic acid, and different chelating agents are used in mineral flotation. For the interaction of collector with the mineral surface, forces like electrostatic, Van der Walls, chemical bonding, and salvation at crystal lattice are collectively responsible. The sulfide ores are most widely treated in the flotation process. The collectors can be classified as anionic, amphoteric, or cationic. Generally, the anionic collectors such as carboxylates, sulfates, sulfonates, phosphates, phosphonates, and hydroxamates are used for the flotation of oxide minerals. These reagents are dissociable, ionizable, and hydrolysable. Cationic collectors having long hydrocarbon chain with amine head are most common reagents in the separation of silicates and quartz minerals in the flotation process. The chelating reagents can be used in flotation as they have selectivity to capture the metal ion-forming chelates. Chelates are a special class of metal complex-forming compounds which may be organic or inorganic with bidentate, tridentate, or tetradentate coordination sphere containing N, O, and S as the donor atoms.