The Effect of Mesogenic Coronas on the Type and Anisotropy of Gold Nanoparticle Superlattices: When Can the Tail Wag the Dog?

Zhao, Yang yang; Li, Yaxin; Cao, Yu; Mehl, Georg H.; Liu, Feng; Ungar, Goran

Abstract

The correlation between the size of nanoparticles, the structure and shape of mesogenic ligands and the ensuing assembly behaviour is not really understood. Closer inspection shows very surprising features. Here, 2- and 4-nm gold nanoparticles (NPs) were synthesized, and grafted with a forked ligand containing two rod-like mesogens in its branches: one cholesterol, the other with azobenzene. The 4-nm NPs also contained n-hexylthiol as co-ligand. They were found to form a FCC cubic superlattice, whereas the 2-nm NPs form hexagonal HCP with weak birefringence, hence with partially oriented ligands. The structures were compared with those of related systems containing a range of different azobenzene-to-cholesterol ratios, all giving body-centred tetragonal superlattices with various degrees of anisotropy. Geometric analysis is presented in terms of the asphericity of the NPs’ surroundings, requirement for space-filling and structural anisotropy. Some general rules are derived to help design the soft corona around the NPs in order to obtain superlattices with the desired structure and anisotropy.

Citation

Zhao, Y. Y., Li, Y., Cao, Y., Mehl, G. H., Liu, F., & Ungar, G. (2023). The Effect of Mesogenic Coronas on the Type and Anisotropy of Gold Nanoparticle Superlattices: When Can the Tail Wag the Dog?. Chemistry: a European journal, 29(11), Article e202203673. https://doi.org/10.1002/chem.202203673

• Journal Article Type: Article
• Acceptance Date: Dec 19, 2022
• Online Publication Date: Jan 26, 2023
• Publication Date: Feb 21, 2023
• Deposit Date: Mar 5, 2023
• Publicly Available Date: Mar 9, 2023
• Journal: Chemistry - A European Journal
• Print ISSN: 0947-6539
• Electronic ISSN: 1521-3765
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 29
• Issue: 11
• Article Number: e202203673
• DOI: https://doi.org/10.1002/chem.202203673
• Keywords: General Chemistry; Catalysis; Organic Chemistry
• Public URL: https://hull-repository.worktribe.com/output/4187960