Bulk-phase water organization

The surfactant used was therefore the potassium salt of DOLPA. The resulting organic phase was a water-in-oil microemulsion since the potassium transfer was accompanied by the coextraction of water molecules. Following liquid-liquid separation of the bulk phases, the organic phase was used for material synthesis. 

The mechanism of the reaction is still under discussion. Hickel et al. [24] proposed that mandelonitrile cleavage by PaHNL occurs at the organic solvent/water interface and not in the aqueous bulk phase (Figure 9.3a). In their recycling... 

Alternatively, the Rh/15-catalysed hydroformylation of 1-tetradecene may proceed in wet micelles 478 (which are water-permeated micelles) or in reversed micelles155,389,406 with solubilisation of an aqueous microdroplet of the Rh/15 catalyst in the organic bulk phase [cf. Figure 4 (A)]. 

Let us consider a system in which two bulk phases, 1 and 2 (e.g., air and water, an organic phase and water), are in contact with each other at a given temperature and pressure. We assume that the two phases are in equilibrium with each other with respect to the amounts of all chemical species present in each. We now introduce a very small amount of a given organic compound i into phase 2 (i.e., the properties of both bulk phases are not significantly influenced by the introduction of the compound). After a short time, some molecules of compound i will have been transferred from phase 2 (reactant) to phase 1 (product) as portrayed in Eq. 3-11. At this point we write down the chemical potentials of i in the two phases according to Eq. 3-36 ... 

When surfactant molecules are dissolved in organic solvents, the head groups cluster together and the hydrocarbon chains point into the bulk phase, forming reverse micelles. If water is trapped in the area of the head groups, the system is termed a microemulsion. Sometimes, a short chain alcohol (e.g. hexanol) is added to aid dispersion. 

Contrary to expectations that enzymes are only active in aqueous solution, activity in almost anhydrous organic solvents was already demonstrated in the 1930s and rediscovered in 1977. It was not water-miscible hydrophilic solvents such as methanol or acetone that proved to be the best reaction media, but hydrophobic water-immiscible solvents such as toluene or cyclohexane. Supposedly, the cause is the partitioning of water between the enzyme surface and the bulk phase of the organic solvent. As comparably hydrophilic solvents such as methanol or acetone can take up basically infinite amounts of water, they strip the remaining water molecules off the enzyme surface. As a consequence, the enzyme is no longer active because it requires a small but measurable amount of water for developing its activity... 

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