Determination of the stoichiometry and the association constant of a thiourea derivatives substrate-cyclodextrin complex

The determination of stoichiometry and association constant of inclusion complex of N-(2-methylphenyl)-N'-(2-methylphenyl) thiourea with hydroxypropyl-b-cyclodextrin (HP-b-CD) by mean of UV-visible spectrophotometry has been investigated. The stoichiometry of the complex formed was determined by continuous variation (Job's plot) method and the overall association constant and its corresponding uncertainties were determined by using Scott's method.