CTAB-PNPs are bound to dichromate ion by electrostatic interaction to form stable non-fluorescent micellar complex which is responsible for the ‘FL quenching’ of CTAB-PNPs.

The activity of periodate as an oxidising agent varies greatly as a function of pH and is capable subtle control. In acid, it is one of the most powerful oxidising agents known, qualitatively and rapidly converting manganese (II) salts to periodate, while in alkaline solution, it is slightly less oxidising than hypochlorite. In alkaline medium, periodate exists as different species involving multiple equilibria [1,2] and it needs to know the active form of oxidant in the reaction. However, there are numerous reports [3] on the oxidation of organic compounds. Guanidine hydrochloride (GH) finds its applications in analytical chemistry, oxidation of guanidine pharmaceuticals and polymer industries. Oxidation of guanidine hydrochloride by permanganate [4] and osmium (VIII) [5] catalysed has been carried out earlier in our laboratory. In continuation of oxidation of guanidine hydrochloride, we have chosen this title reaction for kinetic study. The literature survey reveals that there are no reports on mechanistic studies of oxidation of guanidine hydrochloride by alkaline periodate Thus in order to explore the mechanism of oxidation and to know the active species of periodate in strongly alkaline medium the detail kinetic study of the title reaction is undertaken. Ruthenium (III) acts as an efficient catalyst [7] in several redox reactions and use of RuCl, as a homogenous catalyst in both acid and alkaline media is of interest. Though the mechanism of catalysis depends on the nature of substrate, oxidant, and other experimental conditions, it has been shown that metal ions acts as catalyst by one of these different paths like formation of a complex with reactants or free radicals, etc. The Ruthenium (III) catalysis of a number of organic and inorganic reactions in alkaline media have been studied [8] . The mechanism of the catalysis can be quite complicated due to the formulation of different intermediate complexes, free radicals and different oxidation states of rutheniumn. The uncatalysed reaction has been studied earlier by the same authors [7] , now the catalysed reaction is undertaken to know the changes and to shape out the comparative study between catalysed and uncatalysed reaction. A microscopic amount of osmium (VIII) is sufficient to catalyse there action in alkaline medium and a variety of mechanism are possible. The literature survey reveals that there are no reports on mechanistic studies of osmium (VIII) catalysed oxidation of guanidine hydrochloride by alkaline periodate. Thus in order to explore the mechanism of oxidation and to know the active species of osmium (VII) in strongly alkaline medium the detail kinetic study of the title reaction is undertaken.

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