Two-Dimensional Molecular Networks Via On-Surface Reactions
Lead Research Organisation:
University of Bath
Department Name: Physics
Abstract
The assembly of individual molecular units into molecular networks mediated by on-surface reactions is an exciting emerging paradigm for the synthesis of novel two-dimensional (2D) systems and materials. A famous recent example of such assembly is the formation of graphene nanoribbons starting from small precursor molecules adsorbed on an atomically flat gold surface, which then diffuse and subsequently react with each other to create the ribbon.
Concurrently, recent advances in scanning probe microscopy (most notably in non-contact atomic force microscopy) have allowed one not only to image individual molecules on atomically flat surfaces with unprecedented resolution, but also to identify various products of staged on-surface reactions and, in this way, "visualize" the reaction steps.
Here we extend such principles to a novel class of molecules (borazatruxenes and congeners) to be used as molecular precursors for the assembly of 2D molecular networks: their structure, symmetry and interconnectivity can be varied allowing one to tune the assembly of different 2D networks, which can hence be made to have bespoke electronic properties controlled by the arrangement of molecules in the network. Most importantly, due to the synthetic approach, we will be able to assemble isomeric networks, whereby the same number and type of atoms are interconnected in different ways leading to new materials with new properties. Finally, the electronic properties of the assembled networks will also be investigated (field effect transistors and OLEDs with tunable properties are just two possible outcomes of these new materials).
Moreover, we will attempt to assemble not only on metallic surfaces (which are traditionally used), but also on functional surfaces (such as insulators, graphene or other 2D materials) - if successful, this would represent an extremely powerful, highly flexible route towards the synthesis of novel stacked 2D hybrid heterostructures and multilayer systems, which will be instrumental for the design of entirely novel quantum electronic components.
The core of the work, to be undertaken in the Physics Department, is performing atomically-resolved scanning probe microscopy (i.e. non-contact atomic force and scanning tunneling microscopies) and the associated surface science for both structural and electronic characterization of the on-surface assembled networks; while bespoke molecular precursors will be synthesized in the Chemistry department.
Concurrently, recent advances in scanning probe microscopy (most notably in non-contact atomic force microscopy) have allowed one not only to image individual molecules on atomically flat surfaces with unprecedented resolution, but also to identify various products of staged on-surface reactions and, in this way, "visualize" the reaction steps.
Here we extend such principles to a novel class of molecules (borazatruxenes and congeners) to be used as molecular precursors for the assembly of 2D molecular networks: their structure, symmetry and interconnectivity can be varied allowing one to tune the assembly of different 2D networks, which can hence be made to have bespoke electronic properties controlled by the arrangement of molecules in the network. Most importantly, due to the synthetic approach, we will be able to assemble isomeric networks, whereby the same number and type of atoms are interconnected in different ways leading to new materials with new properties. Finally, the electronic properties of the assembled networks will also be investigated (field effect transistors and OLEDs with tunable properties are just two possible outcomes of these new materials).
Moreover, we will attempt to assemble not only on metallic surfaces (which are traditionally used), but also on functional surfaces (such as insulators, graphene or other 2D materials) - if successful, this would represent an extremely powerful, highly flexible route towards the synthesis of novel stacked 2D hybrid heterostructures and multilayer systems, which will be instrumental for the design of entirely novel quantum electronic components.
The core of the work, to be undertaken in the Physics Department, is performing atomically-resolved scanning probe microscopy (i.e. non-contact atomic force and scanning tunneling microscopies) and the associated surface science for both structural and electronic characterization of the on-surface assembled networks; while bespoke molecular precursors will be synthesized in the Chemistry department.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509589/1 | 01/10/2016 | 30/09/2021 | |||
| 1943873 | Studentship | EP/N509589/1 | 01/10/2017 | 31/07/2021 | Anamaria TRANDAFIR |
| Description | This project focuses on creating new hybrid two dimensional materials via on-surface synthesis from molecular precursors purposefully designed. The hybrid (carbon-boron-nitrogen) character of the networks is important for technological applications where electronic bandgap tuning is required. Up to date, the following milestones have been achieved towards the completion of this project: 1. Study of the electronic structure of the molecular precursors for the 2D networks - via Scanning tunneling microscopy (STM) measurements and density functional theory (DFT) calculations 2. Creation of chiral hydrogen bonded 2D molecular networks - analysis by STM measurements and DFT calculations 3. Successful first trials of inducing on-surface reactions towards a hybrid 2D network |
| Exploitation Route | The discovered chiral 2D networks could be scaled up and used as chiral material for optical applications, while the hybrid covalent 2D networks could be used as 2D materials for electronic applications. |
| Sectors | Electronics,Energy |