High-density liquids

It has been estimated (4) that in most common solvents at room temperature two reactant molecules within a cage of solvent molecules will collide from 10 to a 1000 times before they separate. The number of collisions per encounter will reflect variations in solvent viscosity, molecular separation distances, and the strength of the pertinent intermolecular forces. High viscosities, high liquid densities, and low temperatures favor many collisions per encounter. 

Near the industrial high-pressure distillation of the light hydrocarbons, Cj to C4, another family that includes some low-molecular-weight compounds is the halogenated hydrocarbons, especially the fluorinated ones. These, however, have an exceptionally high liquid density. It is questionable whether they will show the same performance characteristics as the low hydrocarbons. In the absence of evidence, it would be wise to be cautious. 

Immisdbility relative to an SA cosolvent, a VOC exemption (in the US), a high liquid density, and no (or a high) measured flash point matters when selecting an RA cosolvent. 

Quite recently, a modification of this equation has been suggested for high liquid densities and large solute sizes. Notice that under isochoric conditions the free energy of... 

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