Interactions in (l-phenylalanine/l-histidine+0.01mol·kg −1 aqueous β -cyclodextrin) systems at T =(293.15, 298.15, 303.15 and 308.15)K

Abstract Densities ( ρ ) and speeds of sound ( u ) have been measured for ( l -phenylalanine + 0.01 mol · kg −1 aqueous β -cyclodextrin) and ( l -histidine + 0.01 mol · kg −1 aqueous β -cyclodextrin) systems at T  = (293.15, 298.15, 303.15 and 308.15) K using the density and sound velocity Meter DSA 5000 M. The ρ and u values have been utilized to evaluate values of the partial molar volume ( ϕ v ∘ ), transfer partial molar volume ( Δ tr ϕ v ∘ ), partial molar isentropic compressibility ( ϕ k ∘ ), and transfer partial molar isentropic compressibility ( Δ tr ϕ k ∘ ) of the systems studied. The experimentally measured and calculated parameters have been interpreted in terms of host-guest and ion-hydrophilic interactions operative in the systems.