1,5-Naphthalenedisulfonic acid

Химические свойства

Naphthalene-1,5-disulfonic acid [81-04-9]. Armstrong acid, C10H8O6S2, Mr 288.28, crystallizes as the tetrahydrate but dehydrates at 125 ℃ to give the anhydrous acid (mp 240 – 245℃). The disulfonic acid forms an anhydride when treated with oleum below 50℃. This anhydride reacts with ammonia to give a mixture of naphthalene-1,5-disulfonamide and naphthalene-1- sulfonamide-5-sulfonic acid. Treatment of the disodium salt of naphthalene-1,5-disulfonic acid with phosphorus pentachloride at 110℃ gives naphthalene-1,5-disulfonyl chloride (mp 184 ℃), which may also be prepared by chlorosulfonation of naphthalene. Reaction of an aqueous solution of naphthalene-1,5-disulfonic acid with bromide – bromate gives 1,5-dibromonaphthalene so readily that the yellow precipitate may be used to identify very low concentrations of the disulfonic acid.

Профиль безопасности

Very low oral toxicity. Whenheated to decomposition it emits toxic fumes of SOx. Seealso SULFONATES.