The chromaticity of poly(o-anisidine) (POAN) doped with different acids (HA),
HA-doped POAN, has been studied by the spectrophotometric technique and the results
were substantiated by molecular mechanics (MM+) calculations. The observed absorbance
decrease (λ around 720 nm, dark green coloration) with increasing concentration of the inorganic
oxidizing agent (KMnO4) can be attributed to the oxidative hydrolysis mechanism.
The oxidative hydrolysis constant (Kh) is highly dependent on the strength of the acid used.
The HClO4-doped POAN matrix has the ability to store about 128.878 kJ·g−1 chromogenic
energy (CE) at the wavelength 720 nm in a condensed lightweight form. MM+ calculations
suggest that the potential energy (PE) in kJ·mol−1 of the optimum molecular geometric
(OMG) structure of the HClO4-doped POAN matrix is at least two (2.052) times more stable
than the OMG of the base form (POAN-EB) of the POAN matrix. Kinetic parameters
of the oxidative hydrolysis reaction of the HA-doped POAN matrix were deduced from
absorbance variations with time. The results of computer-oriented kinetic analysis indicate
that the rate-controlling step for HA-doped POAN oxidative hydrolysis is governed by the
Ginstling-Bronshein equation that represents three-dimensional diffusion (D4). Activation
parameters for the oxidative hydrolysis of the HClO4-doped POAN matrix were computed
and discussed.