STUDIES ON THE COMPOSITION AND STABILITY OF COMPLEXES OF COPPER (II) WITH SALICYLIC ACID IN AQUEOUS SOLUTION——I. pH-TITRATION METHOD WITH THE METALLIC ION IN EXCESS
YANG Hsiu-Chin Department of Medicinal Chemistry, Szechuan Medical College
Two solutions, in one of which Cu~(2+)∶H_2Sal~* = 10∶1, and in the other, 20∶1, were subjected to pH-titrations with μ? 0.03 at 20±0.5℃. The stability constants of CuSal and CuHSal~+ have been calculated from the results thus obtained by the method of Schwarzenbach. The logarithm of the stability constant of CuSal was found to be 10.5. This figure agrees very well with those obtained by other authors with different methods. The fact that the stability constant of CuHSal~+ turned out to be negative would be an indication of the absence of this cation in aqueous solution under the experimental circumstances.