nitrogen flow the mixture turned to a white suspension after 5 minutes stirring a freshly prepared mixture of 10 ml 1 m hydrogen peroxide and 2 ml of 5 m 20 naoh was added drop wise over 5 minutes the mixture turned immediately dark brown red at the end of the addition some gas evolution was observed after completion of the addition the nitrogen flow was stopped and the stirring was continued for 5 minutes and ph was set with to neutral acidic ph 5 paper with 1 m sulphuric acid the mixture was filtered through a g4 glass frit washed with water and the collected red filtrate and wash diluted to 50 00 ml in a graduated flask from this solution a 1000 u00d7 dilution was made and from the absorption in the uv vis spectrum at 244 278 313 389 and 483 nm the concentration in the stock was calculated and the yield based on extinction of pf 6 analogue in water calculated yield 98 solution contains 5 2 on weight basis of the catalyst stability of aqueous solutions of chloride sulphate and acetate salts are provided solutions of the bleach catalyst with chloride sulphate and acetate anion were brought to ph 2 3 4 and 5 by hydrochloric acid sulphuric acid and acetic acid respectively for the acetate this could only give ph 5 for the lower ph values sulphuric acid was used in the case of acetate the solutions were kept at 37 u00b0 c and after 2 weeks the stability was monitored.