In water at concentration higher than 0.5 M complexation is quantitative without need of stoppers. Typical reactions include metal complexation and acylation. Metallacycle intermediates (19) are the result of the simultaneous complexation and activation of both partners. Metals, however, tend to sorb through electrostatic attraction or surface complexation reactions. Today, liquid solvent extraction procedures involving selective complexation of Th are used. These reactions include adsorption/desorption, precipitation, polymerization, dissolution, complexation and oxidation/reduction. Lariat crown ethers have sidearms that can augment complexation of cation. This occurs as a result of magnesium complexation by carboxyl groups associated with organic matter. It also has preservative properties, perhaps owing to its complexation to metal ions. The molecule undergoes significant conformational change upon complexation. The process proceeds via the initial complexation of ethylene to a Pd(II) center. It binds to metal cations through the thiol groups, which ionize upon complexation. An analogous dark green complex arises from complexation with dimethylamine. A water softener functions by selective complexation with a sulfonate ion exchange resin. These methods include cosolvency, hydrotropism, complexation, ionization, and using surface active agents.