Abstract
Diffusion coefficients and viscosities of tetrabutylammonium dihydrogen phosphate ([NBu(4)](+)[H(2)PO(4)](-)), potassium dihydrogen phosphate (K(+)[H(2)PO(4)](-)), tetrabutylammonium bromide ([NBu(4)](+)[Br](-)), tetrabutylammonium chloride ([NBu(4)](+)[Cl](-)), and biologically relevant phosphate salts adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) were measured in aqueous solutions as a function of concentration across millimolar concentrations. The [NBu(4)](+) cation makes the solutions viscous at high millimolar concentrations, and there was no significant evidence of aggregation of the [H(2)PO(4)](-) anion. At higher millimolar concentrations, ATP, ADP, and AMP aggregate in aqueous solutions. The increasing concentration of ATP and ADP leads to increased activity of three different enzymes: cytochrome c, laccase, and horseradish peroxidase.