Spectrophotometric Study of Complex Formations between Alprazolam and Some Transition Metal Ions in Non Aqueous Solution

In this study, the complexation reaction between Alprazolam (ALP) and metal ions (Zn2+, Ni2+, Cu2+ and Co2+) was investigated by using spectrophotometry in ethanol solvent. The stoichiometry of M+/ALP complexes was calculated by applying the Job, molar ratio and Continuous Changes methods and the relevant diagrams were plotted for each metal ions in each method. The results show that the obtained complexes are 1:3. In the Continuous Changes method a defeat was observed at molar fraction of 0.66 for all complexes, which confirms complexes with 1:3 mole ratio. The formation constants of complexes were determined by using nonlinear least square method (KINFIT software) and it was concluded that the stability of complexes is varied in the order Cu2+> Co2+> Ni2+ > Zn2+. Therefore, Cu is the strongest and Zn formed with Alprazolam ligand is the weakest complex.