Premium
A Small Molecule Walks Along a Surface Between Porphyrin Fences That Are Assembled In Situ
Author(s) -
Haq Sam,
Wit Bareld,
Sang Hongqian,
Floris Andrea,
Wang Yu,
Wang Jianbo,
PérezGarcía Lluïsa,
Kantorovitch Lev,
Amabilino David B.,
Raval Rasmita
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201502153
Subject(s) - porphyrin , scanning tunneling microscope , molecule , chemistry , crystallography , covalent bond , monocrystalline silicon , density functional theory , chemical physics , surface (topology) , materials science , photochemistry , nanotechnology , silicon , computational chemistry , geometry , organic chemistry , mathematics
An on‐surface bimolecular system is described, comprising a simple divalent bis(imidazolyl) molecule that is shown to “walk” at room temperature via an inchworm mechanism along a specific pathway terminated at each end by oligomeric “fences” constructed on a monocrystalline copper surface. Scanning tunneling microscopy shows that the motion of the walker occurs along the [1 $\bar 1$ 0] direction of the Cu surface with remarkably high selectivity and is effectively confined by the orthogonal construction of covalent porphyrin oligomers along the [001] surface direction, which serve as barriers. Density functional theory shows that the mobile molecule walks by attaching and detaching the nitrogen atoms in its imidazolyl “legs” to and from the protruding close‐packed rows of the metal surface and that it can transit between two energetically equivalent extended and contracted conformations by overcoming a small energy barrier.