Addressing the Metal Centers of [2×2] Co^II₄ Grid‐Type Complexes by STM/STS

Abstract

The adsorption of functional molecules on solid substrates is increasingly becoming an important aspect of nanoscience and sensing technology. Molecular and supramolecular electronics, understood as the integration of molecular structures to supplement specific functionalities on an integrated circuit chip, is a promising alternative approach for reducing both the feature size and the cost per functional unit. Driven by its characteristic control of the self-assembly process with nanometer accuracy, supramolecular chemistry has a deep impact on the realization of new concepts in molecular electronics. In particular, it plays a leading role in the future development of electronic devices at the solid-state/air interface; the intrinsic physical properties of supramolecular nanostructures can be screened in view of potential applications in nanotechnology. [1] Recent progress in supramolecular coordination chemistry allows access to a broad variety of transition-metal complexes of grid-type architecture comprising two-dimensional arrays of metal ions interconnected by a set of organic

Self‐Assembly of Alkoxy‐Substituted Bis(hydrazone)‐Based Organic Ligands and of a Metallosupramolecular Grid on Graphite

“…Ionic charges introduced by the metal centres decrease the affinity of the grid for the apolar HOPG substrate. [24,25,31,32] Highly stable metal-grid monolayers formed by drop casting on HOPG of a dilute acetone solution containing a cobalt(II) [2 2] grid complex based on a polypyridine ligand (4,6-bis(2',2''-bipyrid-6'-yl)-2-phenylpyrimidine) have been reported. [24,31,33,34] Interestingly, the orientation of the grids relative to the surface plane was found to depend on the position of methyl substituents on the ligand.…”

“…[24,25,31,32] Highly stable metal-grid monolayers formed by drop casting on HOPG of a dilute acetone solution containing a cobalt(II) [2 2] grid complex based on a polypyridine ligand (4,6-bis(2',2''-bipyrid-6'-yl)-2-phenylpyrimidine) have been reported. [24,31,33,34] Interestingly, the orientation of the grids relative to the surface plane was found to depend on the position of methyl substituents on the ligand. [24,25] It was suggested that the different packing of the grids on HOPG could be attributed to differences in intermolecular interactions between grids as well as to differences in the counterions.…”

Chemische Strategien für den Aufbau molekularer Logikelemente zur Addition und Subtraktion

“…[71] Experimente mit Rastertunnelmikroskopie (STM) und Rastertunnelspektroskopie (STS) haben ergeben, dass sich individuelle Metallionenzentren in diesen Arrays adressieren lassen. [72] [6,13,23,74] Auf dieser Grundlage wurden einfache Logikgatter, kombinatorische Logikschaltkreise (Addierer) und eine komplexere Zustandsmaschine mit einem internen Speicher entwickelt. [75] Es muss allerdings bedacht werden, dass diese Experimente bis jetzt zumeist auf die Gasphase begrenzt sind.…”

Synthesis and complexation properties of novel triazoyl-based ferrocenyl ligands

“…In particular, grid-type coordination arrays, which consist of a regular array of metal cations arranged between two perpendicular sets of parallel ligands, have been extensively studied over the past years [3][4][5][6]. The resulting compounds present interesting physico-chemical properties, such as electrochemical [7,8], optical [8], electronic [9], magnetic [10][11][12] or catalytic activity [13]. The choice of suitable ligands and metal ions is hence crucial for their synthesis.…”