One-Dimensional Double Wires and Two-Dimensional Mobile Grids: Cobalt/Bipyridine Coordination Networks at the Solid/Liquid Interface

Abstract

Various architectures have been generated and observed by STM at a solid/liquid interface resulting from an in situ chemical reaction between the bipyridine terminal groups of a ditopic ligand and Co(II) ions. Large monodomains of one-dimensional (1D) double wires are formed by Co(II)/ligand coordination, with polymer lengths as long as 150 nm. The polymers are organized as parallel wires 8 nm apart, and the voids between wires are occupied by solvent molecules. Two-dimensional (2D) grids, showing high surface mobility, coexist with the wires. The wires are formed from linear chain motifs where each cobalt center is bonded to two bipyridines. 2D grids are generated from a bifurcation node where one cobalt bonds to three bipyridines. Surface reconstruction of the grids and of the 1D wires was observed under the STM tip. As an exciting result, analysis of these movements strongly indicates surface reactions at the solid/liquid interface.Letter pubs.acs.org/JPCL

Visualization and Comprehension of Electronic and Topographic Contrasts on Cooperatively Switched Diarylethene-Bridged Ditopic Ligand

“…The bpy-DAE-bpy molecules are observed in the trans-bpy conformation with the ditopic bipyridine groups oriented in opposite directions. The "S" shaped appearance of bpy-DAE-bpy molecules is in line with our previous studies of bpy-X-bpy derivatives (X= azobenzene, biEDOT or Fluorene)[38,[66][67][68]. Since the molecules were irradiated in solution with UV, the surface is seen to be overwhelmingly covered by CF isomers under STM (Figure1b).…”

“…The bpy-DAE-bpy ligand is depicted in Scheme 1. A series of ditopic ligands (bpy-X-bpy) with variable central bridges has been reported previously by the authors' group [38,[66][67][68]. The bpy-X-bpy building blocks can adopt either the cis-bpy or the trans-bpy configurations, depending on the protonation of the bipyridine units.…”

“…The details of the DFT calculation are given in the method section. The orientation of the pyridine rings is the result of a balance between the established N•••H-N hydrogen bond [53,[66][67][68] and a small van der Waals attraction [55,68,[71][72][73][74] in the ortho pyridine. As a consequence, the interaction between the two bipyridine rings (each from a neighboring molecule) is very strong (stronger than between two pyridine rings).…”

Well-organised two-dimensional self-assembly controlled byin situformation of a Cu(ii)-coordinated rufigallol derivative: a scanning tunnelling microscopy study

“…Metal coordination that forms supramolecular complexes in 2D molecular assemblies, including oligomers and polymers, has been studied. 3 Two-dimensional structural changes associated with the addition of metal ions can be used to judge whether or not a metal complex has been formed. While the apparent formation of metal-coordinated oligomers/polymers has been confirmed by STM, to our knowledge, only a few studies have focused on the effect of the metal-coordination process, that is, in situ or ex situ , on 2D molecular network formation.…”

Long-Range Charge Transport in Diazonium-Based Single-Molecule Junctions

“…4-Aminophenyl-2,2′:6′,2″-terpyridine, 5-aminophenyl-2,2′-bipyridine, and their corresponding Co and Ru complexes were synthesized following previously reported procedures. ,,− Co­(tpy) 2 and Ru­(tpy) 2 have the same length (2 nm) but differ in the metal centers. The two amino terminal groups act either as electrochemical active groups for grafting onto the bottom electrode or as anchoring groups to be picked up by the Au STM tips.…”