The acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. The stoichiometric equilibrium constants were determinedat 25 °C and constant ionic strength 0.1 mol L-1 (NaCl). The acidity constants pK1=1.58±0.05and pK2=11.67±0.07 were found by potentiometry, and pK1=1.54±0.02 and pK2=11.61±0.03 bymulti-wavelengths spectrophotometry. Potentiom...

The complexation reactions between 4-(2-pyridy1azo)-resorcinol and Cd ,H g and Pb io ns have been investigated in acetonitrile-dimethyEomamide mixtures at various temperatures using a spectrophotometric technique. The stoichiometry and the formation constants of the complexes formed in solution were calculated by computer refinement of absorbance-mole ratio data using nonlinear least-square ...

The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12-crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation cons...

The formation constants and Gibbs free energy for the interaction of RnSnClm (n = m = 2, R = Me, Ph, n-Bu or n = 4, m = 0, R = Ph) compounds as acceptors, with ML complexes (H2L = N,N'-bis(salicylidene)-2-aminobenzylamine (salabza-H2) and its derivatives, M = Mn2+ or Zn2+), as donors in N,N'-dimethylformamide (DMF) as solvent were studied. These parameters were measured by using UV-vis spectrop...

formation of the molecular complexes between meso-tetraphenylporphyrin (tpp) and the p-acceptors 2,3-dichloro-5,6-dicyanobenzoquinone (ddq) and tetracyanothylene (tcne) in chloroform solution was investigated spectrophotometrically. the formation constants of the resulting 1:1 molecular complexes were determined using the benesi-hildebrand and nash methods. the tpp-ddq proved to be more stable ...

the formation of charge-transfer complexation between dibenzo-15-crown-5 (db15c5) and benzo-12-crown-4 (b12c4) (donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (dcm) and 1,2-dichloroethane (dce) solution at 25°c. the change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. values of formation cons...

the formation constants and gibbs free energy for the interaction of rnsnclm (n = m = 2, r = me, ph, n-bu or n = 4, m = 0, r = ph) compounds as acceptors, with ml complexes (h2l = n,n'-bis(salicylidene)-2-aminobenzylamine (salabza-h2) and its derivatives, m = mn2+ or zn2+), as donors in n,n'-dimethylformamide (dmf) as solvent were studied. these parameters were measured by using uv-vis spectrop...