The synthesis of novel functional amphiphilic dipodal NiII (1) and ZnII (2) Schiff base complexes and the preparation/characterization and optical properties of Langmuir–Schäfer (LS) multilayer films are reported. The existence of stacked 3D aggregates is observed for all films, as established by the combination of reflection spectroscopy and Brewster angle microscopy. Although aggregate formation does not involve major electronic changes, as evidenced by analysis by absorption spectroscopy, fluorescence emission is much more sensitive to the chemical environment, and complete quenching is observed in the multilayer LS aggregates. However, in the limit of negligible interchromophore interactions, achieved by means of mixed LS multilayer films the fluorescence is restored by using arachidic acid as a spacer diluent, and LS layers of 2 behave as related self-assembled monolayers.
Langmuir-Schäfer Films of New Functional Amphiphilic Nickel(II) and Zinc(II) Schiff-Base Complexes
GIANCANE, Gabriele;VALLI, Ludovico
2008-01-01
Abstract
The synthesis of novel functional amphiphilic dipodal NiII (1) and ZnII (2) Schiff base complexes and the preparation/characterization and optical properties of Langmuir–Schäfer (LS) multilayer films are reported. The existence of stacked 3D aggregates is observed for all films, as established by the combination of reflection spectroscopy and Brewster angle microscopy. Although aggregate formation does not involve major electronic changes, as evidenced by analysis by absorption spectroscopy, fluorescence emission is much more sensitive to the chemical environment, and complete quenching is observed in the multilayer LS aggregates. However, in the limit of negligible interchromophore interactions, achieved by means of mixed LS multilayer films the fluorescence is restored by using arachidic acid as a spacer diluent, and LS layers of 2 behave as related self-assembled monolayers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
