9- Chromogenic energy of poly(o-anisidine) vanished via oxidative hydrolysis Mechanism

Seddique M Ahmed

Abstract: Chromogenic energy (CE) of poly(o-anisidine) doped with different acids (HA-doped POAN) has been studied by the spectrophotometric technique and supported by molecular mechanics (MM) calculations.. The decrease of the absorbance (λ = 720 nm, dark green). with increasing the concentration of the inorganic oxidizing agent (KMnO₄) could be attributed to the oxidative hydrolysis mechanism. The oxidative hydrolysis constant (K_h) is highly dependent on the strength and the acid used. HClO₄-doped POAN matrix has the ability to store CE about 128.878 kJ g^-1 at 720 nm in a condensed lightweight form. MM calculations suggests that the potential energy (PE) in kJ mol^-1 of the optimum molecular geometric (OMG) structure of HClO₄ -doped POAN matrix is at least twice times (2.052) of magnitude more stable than that of the OMG of the base form of POAN matrix. Kinetic parameters of the oxisdative hydrolysis reaction were deduced employing a computer-oriented kinetic analysis of the absorbance (A) at 720 nm against the time (t) data. The results obtained indicate that the rate controlling process is governed by the Ginstling-Brounshetin-equation three-dimensional diffusion (D4). The proposed mechanism for the oxidative hydrolysis of HA-doped POAN matrix is also substantiate by MM calculations. Activation parameters for the rate of the hydrolysis oxidative process of HClO₄-doped POAN chain have been computed and discussed.

Keywords: Chromaticity, Chromomeric energy, Poly(o-anisidine), Activation Parameters, Molecular Mechanics (MM+) Calculations.

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