Controlling on-surface polymerization by hierarchical and substrate-directed growth

Abstract

A key challenge in the field of nanotechnology, in particular in the design of molecular machines, novel materials or molecular electronics, is the bottom-up construction of covalently bound molecular architectures in a well-defined arrangement. To date, only rather simple structures have been obtained because of the limitation of one-step connection processes. Indeed, for the formation of sophisticated structures, step-by-step connection of molecules is required. Here, we present a strategy for the covalent connection of molecules in a hierarchical manner by the selective and sequential activation of specific sites, thereby generating species with a programmed reactivity. This approach leads to improved network quality and enables the fabrication of heterogeneous architectures with high selectivity. Furthermore, substrate-directed growth and a preferred orientation of the molecular nanostructures are achieved on an anisotropic surface. The demonstrated control over reactivity and diffusion during covalent bond formation constitutes a promising route towards the creation of sophisticated multi-component molecular nanostructures.

MARTINI Model for Physisorption of Organic Molecules on Graphite

“…Moreover, a better knowledge of the mechanism of formation and reorganization of these aggregates is relevant for gaining a better insight in the phenomena of molecular self-assembly 11−15 and in view of aggregate poststabilization. 16,17 Noteworthy events during the formation and reorganization take place at shorter time scales than those of the commonly used techniques for the study of these aggregates, and therefore only little is known about them. To tackle this issue, molecular dynamics (MD) is proposed for its ability to simulate events on the appropriate time scales.…”

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons

“…The latter can act as either logic gates or molecular wires for the transport of individual electrons, photons or magnetic moment in a similar way as observed for natural networks of neurons that serve as the basis for information processing and storage in the brains of living organisms [2][3][4][5][6] . However, current approaches for developing molecularly interconnected networks mainly rely on covalent chemistry 7,8 . Self-assembly as a tool to form long-range interconnected 1D-or 2D-nanostructures with tuneable optical, electrical and magnetic properties may represent a possible solution towards the mass production of molecular circuits.…”

Phase behaviour of self-assembled monolayers controlled by tuning physisorbed and chemisorbed states: A lattice-model view

“…Self-assembly of halogenated aromatic molecules can be used to form covalently bonded networks, such as brominated tetraphenylporphyrin on Au(111) [4] and the simpler halogenated benzene on Cu(111), Ag(111) or Au(111) [17]. Halogenation can also influence the self-assembled structures of polyaromatic molecules.…”

“…The self-assembly of functionalised molecules on surfaces is key for the development of novel 2D devices [1] for a variety of applications [2] including graphene and polymer formation [3][4][5], and semiconductor nanostructures [6,7]. Realisation of these applications requires the formation of highly-ordered self-assembled structures on surfaces.…”