The construction and characterization of novel self-assembled thin films of
zirconium phosphonate/1,4,5,8-naphthalenediimides is described. The films
were grown on silica or quartz substrates by deposition of alternated layer
s of Zr+4 and N,N'-di(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (DPN). F
ilms containing up to 16 layers were obtained. Film growth, followed by eit
her absorption spectroscopy or ellipsometry, was linear with the number of
layers, showing that equal amounts of material were deposited in each cycle
. Atomic force microscopy (AFM) images showed, however, that the films were
microscopically not homogeneous, but rather constituted of crystallites of
DPN. When irradiated, the initially colorless films turned to a persistent
pinky color reminiscent of that of DPN anion radical. (C) 2000 Elsevier Sc
ience S.A. All rights reserved.