IDENTIFICATION OF THE PHASES IN THE SYSTEM BENZOTRIAZOLE-COPPER (I ORII)-WATER

The preparation and the stability of different complexes in the system benzotriazole (BTAH), copper(I) or (II), and water are examined. Copp er(I) gives 2 anhydrous complexes; the polymorphic form obtained depen ds on the associated anion present during the precipitation. Cu(BTA) f orm I is obtained with iodide while chloride or cyanide or thiocyanide give Cu(BTA) form II, a well crystallized and stable form. On storage Cu(BTA) form I transforms into Cu(BTA) form II within 4 or 5 weeks at 20 degrees C. Copper(II) gives 2 hydrated complexes : quasi amorphous Cu(BTA)(2).2H(2)O (unstable) and crystallized Cu(BTA)(2).H2O (stable) . On heating at 200 degrees C the monohydrate copper (II) complex show s departure of water molecules to yield successively a hemihydrate and an anhydrous complex copper (II); these phases spontaneously rehydrat es in the presence of moisture to Cu(BTA)(2).H2O.