STUDY OF THE FORMATION AND PHOTOCHEMISTRY OF AN ELECTRON DONOR-ACCEPTOR (EDA) COMPLEX BETWEEN BENZALDEHYDE AND METHYLVIOLOGEN IN SOLUTION

The interaction between benzaldehyde (PhCHO) and methylviologen (MV(2+)) was studied in ethanol-water solutions. An absorption band was observed, with lambda(max)>400 nm, shifted by a change in solvent polarity. This is not due to either of the individual components and can be assigned to a complex formed via interaction of PhCHO and MV(2+). A new fluorescence band with an emission maximum at 530 nm can also be assigned to this complex. Equilibrium constants (K-eq) and molar extinction coefficients (epsilon(0)) for the complex were determined and the effect of temperature on the equilibrium was studied. The photochemistry and photophysics of the complex were also investigated by measuring the fluorescence lifetime and quantum yield and photolysis quantum yield in ethanol-water solutions.