Phenoxyaluminum(salophen) Scaffolds: Synthesis, Electrochemical Properties, and Self-Assembly at Surfaces of Multifunctional Systems

en

24

46

11954

11960

2018-03-30

2018-08-14

09476539

Chemistry - A European Journal

Salophens and Salens are Schiff bases generated through the condensation of two equivalents of salicylaldehyde with either 1,2‐phenylenediamines or aliphatic diamines, respectively. Both ligands have been extensively exploited as key building blocks
Show moreSalophens and Salens are Schiff bases generated through the condensation of two equivalents of salicylaldehyde with either 1,2‐phenylenediamines or aliphatic diamines, respectively. Both ligands have been extensively exploited as key building blocks in coordination chemistry and catalysis. In particular, their metal complexes have been widely used for various catalytical transformations with high yield and selectivity. Through the modification of the phenol unit it is possible to tune the steric hindrance and electronic properties of Salophen and Salen. The introduction of long aliphatic chains in salicylaldehydes can be used to promote their self‐assembly into ordered supramolecular structures on solid surfaces. Herein, we report a novel method towards the facile synthesis of robust and air‐stable [Al(Salophen)] derivatives capable of undergoing spontaneous self‐assembly at the graphite/solution interface forming highly‐ordered nanopatterns. The new synthetic approach relies on the use of [MeAlIII(Salophen)] as a building unit to introduce, via a simple acid/base reaction with functionalized acidic phenol derivatives, selected frameworks integrating multiple functions for efficient surface decoration. STM imaging at the solid/liquid interface made it possible to monitor the formation of ordered supramolecular structures. In addition, the redox properties of the Salophen derivatives functionalized with ferrocene units in solution and on surface were unraveled by cyclic voltammetry. The use of a five‐coordinate aluminum alkyl Salophen precursor enables the tailoring of new Salophen molecules capable of undergoing controlled self‐assembly on HOPG, and thereby it can be exploited to introduce multiple functionalities with subnanometer precision at surfaces, ultimately forming ordered functional patterns.
Show less

Wiley

Chem. Eur. J.

ACL

LabEx project Chemistry of Complex Systems (ANR‐10‐LABX‐0026_CSC)

European Community through the project EC FP7 ICT‐MOLARNET (318516) and the European Research Council project SUPRAFUNCTION (GA‐257305)

Chimie/Matériaux

cyclic voltammetry
HOPG
salophen
self-assembly
STM microscopy

Dipartimento di Chimica “G. Ciamician” ALMA MATER STUDIORUM Università di Bologna Via Selmi 2, 40126, Bologna,Italy.

aut

International