posted on 2013-06-20, 00:00authored byJoachim Reichert, Matthias Marschall, Knud Seufert, David Ecija, Willi Auwärter, Emmanuel Arras, Svetlana Klyatskaya, Mario Ruben, Johannes V. Barth
The
organic and metal-directed assembly of a prochiral carbonitrile
(CN) oligophenyl molecule on a smooth noble metal substrate was investigated
by combined scanning tunneling microscopy and computational modeling.
The molecule is functionalized with two CN groups in meta and para positions of the terminating phenyl rings
of the p-terphenyl backbone. Upon deposition on a
Ag(111) surface, we observe two different organic supramolecular networks,
one of them reflecting a chiroselective assembly. After coevaporating
small amounts of Co, a hybrid network comprising both CN–phenyl
and metal coordination bond motifs could be observed. Intriguingly,
the CN group in the para position is favored for
the metal coordination, whereas the meta group remains
in a CN–phenyl motif. Computational modeling suggest that the
high stability of the meta CN–phenyl motif
is causing this selective interaction. An increase of the metal adatom
ratio eventually induces divergent assembly of a room-temperature
stable 2D random metal–organic network.