ok let me put this to rest.
chlorine dioxide, also known as chlorine peroxide [math]ClO_2[/math]
is extremely unstable because chlorine can't really have a +4 oxidation state or formal charge. it decomposes in an explosive manner to form chlorine and oxygen. it will oxidize things.
according to my merck index (13th edition):
"strongly oxidizing, yellow to reddish-yellow gas at room temp. unpleasant odor similar to that of chlorine and reminiscent of that of nitric acid. unstable in light; stable in dark if pure, but chlorides catalyze its decompn even in the dark. REACTS VIOLENTLY WITH ORGANIC MATERIALS. in concns in excess of 10% at atm pressure easily detonated by sunlight, heat, contact with mercury or carbon monoxide. mp=-59 celsius; bp= 11 celsius. sol in water (3.01g/l at 25 celsius and 34.5mm Hg) with slight hydrolysis to chlorous and chloric acid; sol in alkaline and sulfuric acid solns. solid is yellowish-red crystalline mass; liquid is reddish-brown.