Wilkinson, Luke A. and Bennett, Troy and Grace, Iain and Hamill, Joseph and Wang, Xintai and Au-Yong, Sophie and Ismael, Ali and Jarvis, Samuel and Hou, Songjun and Albrecht, Tim and Cohen, Lesley F. and Lambert, Colin and Robinson, Benjamin and Long, Nicholas J. (2022) Assembly, structure and thermoelectric properties of 1,1’-dialkynylferrocene ‘hinges’. Chemical Science, 13 (28). 8380–8387. ISSN 2041-6520
Full text not available from this repository.Abstract
Dialkynylferrocenes exhibit attractive electronic and rotational features that make them ideal candidates for use in molecular electronic applications. However previous works have primarily focussed on single-molecule studies, with limited opportunities to translate these features into devices. In this report, we utilise a variety of techniques to examine both the geometric and electronic structure of a range of 1,1’-dialkynylferrocene molecules, as either single-molecules, or as self-assembled monolayers. Previous single molecule studies have shown that similar molecules can adopt an ‘open’ conformation. However, in this work, DFT calculations, STM-BJ experiments and AFM imaging reveal that these molecules prefer to occupy a ‘hairpin’ conformation, where both alkynes point towards the metal surface. Interestingly we find that only one of the terminal anchor groups binds to the surface, though both the presence, and nature of the second alkyne affects the thermoelectric properties of these systems. First, the secondary alkyne acts to affect the position of the frontier molecular orbitals, leading to increases in Seebeck coefficient. Secondly, theoretical calculations suggested that rotating the secondary alkyne away from the surface acts to modulate thermoelectric properties. This work represents the first of its kind to examine the assembly of dialkynylferrocenes, providing valuable information about both their structure and electronic properties, as well as unveiling new ways in which both of these properties can be controlled.