Further mechanistic orientation for the oxidation reaction between alkaline permanganate and poly galacturonate methyl ester. Novel spectrophotometric tracer of intrahypomanganate(V) - Intermediate

The kinetics of formation of the green manganate(VI) intermediate complex formed during the oxidation of pectin polysaccharide (poly galacturonate methyl ester) (PGME) by MnO4- in alkaline solution at pH ⩾ 12 have been studied. The rate law was suggested to be: rate = kobs.[MnO4-]. The reaction was found to be base - catalyzed and fractional second - order in [PGME]. The activation parameters have been evaluated and discussed. A reaction mechanism was suggested according to the experimental data. A new blue hypomanganate(V) coordination polymer intermediate sol was spectrophotometrically detected for the first time for pectin (poly galacturonate methyl ester) oxidation reaction. A further mechanistic presentation was proposed.