Photoinduced electron transfer from phenanthroimidazole to nano WO3, CuO ZrO2 and Al2O3. LUMO – CB energy binding efficiency relationship

Abstract

A new kind of fluorophore 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d] imidazole has been synthesized and characterized by 1H NMR, 13C NMR and mass spectral studies. The dynamics of photoinduced electron injection and energy transfer from phenanthroimidazole to CuO, ZrO2, WO3 and Al2O3 nanocrystals has been studied by Fourier transform infrared spectroscopy (FT-IR), absorption, fluorescence and lifetime spectroscopic methods. The association between nanocrystals and phenanthroimidazole is explained by both absorption and fluorescence quenching data. The distance between phenanthroimidazole and nanocrystals as well as the critical energy transfer distance has been obtained. The free energy change (ΔGet) for electron injection has also been deduced. Qualitative relationship exists between the efficiency of binding with the LUMO – CB energy gap and also the efficiency of binding with the HOMO – CB energy gap.