Molecular Templates on Surfaces by Exploiting Supramolecular Chemistry in Langmuir–Blodgett Monolayers

Abstract

Attaining precise control over molecular arrangements is of paramount importance for numerous applications in nanotechnology, particularly in constructing molecular templates to accurately immobilize target materials on surfaces. A strategic combination of supramolecular and interfacial chemistry may serve to build a well-organized molecular network, enabling the subsequent location of target molecules on specific positions of a surface. A supramolecular complex (compound 1) comprised of a melamine unit forming hydrogen bonds with dendritic arms terminated in a coumarin unit is utilized, which readily undergoes photodimerization. The research demonstrates the formation of well-organized Langmuir films of compound 1 which can be transferred on substrates at low surface pressures adopting a lying-flat orientation. Upon irradiation of the pristine films at 365 nm the coumarin units undergo photo-cross linking, leading to the formation of a compact photo-crosslinked film. Incubation of these photo-crosslinked films in a solution containing 1-hexanethiol results in the withdrawal of the melamine and the chemisorption of two thiol molecules per each melamine unit. The nanopores created by the removal of the melamine core are attributed to the disruption of hydrogen bonds in compound 1 by the thiols. This precisely defined molecular network holds significant promise as a template for orchestrating the arrangement of functional materials on surfaces.