ja8b02968_si_002.cif (11.41 MB)
Sorting of Molecular Building Blocks from Solution to Surface
dataset
posted on 2018-05-16, 00:00 authored by Hodaya Keisar, Graham de Ruiter, Aldrik H. Velders, Petr Milko, Antonino Gulino, Guennadi Evmenenko, Linda J. W. Shimon, Yael Diskin-Posner, Michal Lahav, Milko E. van der BoomWe demonstrate that
molecular gradients on an organic monolayer
is formed by preferential binding of ruthenium complexes from solutions
also containing equimolar amounts of isostructural osmium complexes.
The monolayer consists of a nanometer-thick assembly of 1,3,5-tris(4-pyridylethenyl)benzene
(TPEB) covalently attached to a silicon or metal-oxide surface. The
molecular gradient of ruthenium and osmium complexes is orthogonal
to the surface plane. This gradient propagates throughout the molecular
assembly with thicknesses over 30 nm. Using other monolayers consisting
of closely related organic molecules or metal complexes results in
the formation of molecular assemblies having an homogeneous and equimolar
distribution of ruthenium and osmium complexes. Spectroscopic and
computational studies revealed that the geometry of the complexes
and the electronic properties of their ligands are nearly identical.
These subtle differences cause the isostructural osmium and ruthenium
complexes to pack differently on modified surfaces as also demonstrated
in crystals grown from solution. The different packing behavior, combined
with the organic monolayer significantly contributes to the observed
differences in chemical composition on the surface.