Oriented crystalline monolayers and bilayers of 2 x 2 silver(I) grid architectures at the air-solution interface: their assembly and crystal structure elucidation
Oriented crystalline monolayers, approximately 14 A thick, of a 2 x 2 Ag+ grid complex, self-assembled at the air-solution interface starting from an water-insoluble ligand 3,6-bis[2-(6-phenylpyridine)]pyridazine spread on silver-ion-containing solutions, were examined by grazing-incidence X-ray diffraction and specular X-ray reflectivity using synchrotron radiation. The monolayer structure was refined, including a determination of the positions of the counter-ions, with the SHELX-97 computer program. The monolayers were transferred from the interface onto various solid supports and visualized by scanning force microscopy, and characterized by X-ray photoelectron spectroscopy in terms of molecular structure. On surface compression, the initial self-assembled monolayer undergoes a transition to a crystalline bilayer in which the two layers, almost retaining the original arrangement, are in registry. Such a phase transition is of relevance to the understanding of crystal nucleation.
Weissbuch
I
Department of Materials and Interfaces, The Weizmann Institute of Science, Rehovot, Israel. csweisbu@weizmann.ac.il
Baxter
PN
Kuzmenko
I
Cohen
H
Cohen
S
Kjaer
K
Howes
PB
Als-Nielsen
J
Lehn
JM
Leiserowitz
L
Lahav
M