Abstract
The study reveals that the bulky substituents and extensive delocalization from conjugated aromatic groups can have negative influence on the solubilization of thiophene derivatives by micellar solution of anionic surfactant, Sodium dodecyl sulphate (SDS).
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•SDS causes shift in spectra of BPTS and BTS.•BTS has greater degree of binging and partition with SDS than BPTS.•Electrostatic and hydrophobic forces favour partitioning.
The present study describes the detailed investigations of the solubilization of thiophene derivatives i.e. 5-(2-(benzyloxy) phenyl) thiophene-2-sulfonamide (BPTS) and 5-bromothiophene-2-sulfonamide (BTS) by micellar solution of anionic surfactant, Sodium dodecyl sulphate (SDS). The interaction of SDS in the solution containing aforementioned compounds was investigated by electrical conductivity and UV–vis spectroscopy. The data of electrical conductivity was used to calculate thermodynamic parameters like free energy (ΔGm), enthalpy (ΔHm) and entropy (ΔSm) of micellization of SDS in the presence of thiophenes, whereas UV–vis spectroscopy was used to calculate the extent of solubilization in term of partition coefficient (Kx), free energy of partition (ΔGp), binding constant (Kb) and free energy of binding (ΔGb). The experimental results from thermodynamic parameters reveal that the solubilization of said thiophene derivatives was spontaneous, in addition to enthalpy and entropy driven. The large molecular size, aromatic nature with extensive delocalization and less charge density of BPTS was found to have a negative impact on solubilization of this compound, which was observed from poor binding capacity and inadequate partitioning displayed by this compound.