Beryllium perchlorate is an inorganic chemical compound with the formula Be(ClO4)2·nH2O, where n is 2 or 4. All forms are white, hygroscopic, and water-soluble solids.
Synthesis and reactions Beryllium perchlorate tetrahydrate, Be(ClO4)2·4H2O, is produced from the reaction of beryllium oxide and concentrated perchloric acid followed by the evaporation of the solution:J. Marignac, Ann. Chim., 4, 45 (1873) BeO + 2 HClO4 → Be(ClO4)2 + H2O The dihydrate can be similarly prepared by the reaction of beryllium chloride and hydronium perchlorate at 60 °C.
Heating of the tetrahydrate does not produce the anhydrous form; it instead decomposes at 140 °C, producing an unidentified basic beryllium perchlorate, and if this compound is heated to 260 °C, it decomposes to beryllium oxide. Similarly, if the dihydrate is heated to 200 °C, it decomposes to basic beryllium perchlorate (Be4O(ClO4)6), which then decomposes at 270 °C to BeO.
The tetrahydrate and dihydrate dissolves in water to form the [Be(H2O)4]2+ ion, which then partially hydrolyzes to the trimeric ion [Be3(OH)3(H2O)6]3+. They also dissolve in acetone which then can react with triphenylphosphine oxide to form Be(OPPh3)4(ClO4)2.
Structure The structure of the dihydrate, which was probed by IR spectroscopy, consists of discrete [Be(H2O)4]2+ and [Be(ClO4)4]2– ions.
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