Ox i da tive poly mer iza tion re ac tion of 8-hydroxyquinoline (HQ) in dif fer ent me dia has
been stud ied ex per i men tally by spec tro pho to met ric tech nique and con firmed
computationally by mo lec u lar me chan ics (MM+) cal cu la tions. MM+ cal cu la tions
showed that the PE of the op ti mum mo lec u lar geo met ric (OMG) of the an ionic HQ
(HQ-NaOH) form is about two (1.985) times greater than the PE in the protonated
(HQ-HCl) form. PE of the OMG struc ture of the PHQ was com puted (–30.651 kJ mol–1).
These cal cu la tions in di cate that the ma trix is highly sta ble. The ox i da tion con stant (Kox)
of the an ionic form (HQ-NaOH) is about twice (2.02) greater than that of the protonated
(HQ-H2SO4) form. The pro posed pro ce dure was suc cess fully ap plied for the ox i da tion of
diiodohydroxyquinoline in streptoquin (SQ) (anti-di ar rhea, tab lets). The Kox of HQ in
SQ was also found to be lower than the Kox in syn thetic (HQ) so lu tion. Ki netic pa ram e ters
of the ox i da tive poly mer iza tion of the an ionic form of HQ (HQ-NaOH) were de duced on
the ba sis of absorbance vari a tions. The re sults of com puter-ori ented ki netic anal y sis in di -
cate that the rate-con trol ling step of the HQ poly mer iza tion is gov erned by
Ginstling-Bronstein equa tion rep re sent ing the three-di men sional dif fu sion (D4). Ac ti va -
tion pa ram e ters of the ox i da tive poly mer iza tion of the an ionic form of HQ (HQ-NaOH)
were com puted and dis cussed.