Potentiometeric study of the transition metal (II) ion complexes with drug diazepam[7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepine-2-one]

The potentiometer studies have been carried out on metal complexes of Co (II); Mn (II); Cu (II); & Zn (II) with drug diazepam [7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepine-2-one]. The proton ligand dissociation constant of the ligand & the formation constants of their metal complexes have been determined by Albert Serjent method at 25 +/- 1 degrees C & an ionic strength 0.1 M KNO3 in 50 : 50 % (v/v) ethanol-water medium. From the variation of pK values with temperature the values of Delta G, Delta H & Delta S were also evaluated in aqueous medium at 25 degrees C.