title: Binding and Packing in Two-Component Colloidal Quantum Dot Ligand Shells: Linear versus Branched Carboxylates.
abstract: In this work, we present a combined experimental and theoretical analysis of two-component ligand shells passivating CdSe quantum dots. Using nuclear magnetic resonance spectroscopy, we first show that exposing oleate-capped quantum dots to primary carboxylic acids results in a one-for-one exchange that preserves the overall ligand surface concentration. Exposure to straight-chain acids leads to a binary ligand shell that behaves as an ideal mixture and that has a composition matching the overall acid composition of the dispersion. In the case of branched-chain acids, the exchange is restricted to about 25% of the original ligands. Based on molecular dynamics simulations, we argue that this behavior reflects the more favorable packing of oleates compared to branched carboxylates on the (100) facets of CdSe quantum dots.
authors.forename: Kim
authors.initials: K
authors.lastname: De Nolf
authors.affiliation: Department of Theoretical Chemistry, Vrije Universiteit , 1081 HV Amsterdam Netherlands.
authors.forename: Salvatore M
authors.initials: SM
authors.lastname: Cosseddu
authors.affiliation: ARC Centre of Excellence in Exciton Science, and Department of Materials Science and Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Jacek J
authors.initials: JJ
authors.lastname: Jasieniak
authors.forename: Emile
authors.initials: E
authors.lastname: Drijvers
authors.forename: José C
authors.initials: JC
authors.lastname: Martins
authors.affiliation: Department of Theoretical Chemistry, Vrije Universiteit , 1081 HV Amsterdam Netherlands.
authors.forename: Ivan
authors.identifier: 0000-0003-3467-9376
authors.initials: I
authors.lastname: Infante
authors.forename: Zeger
authors.identifier: 0000-0002-7041-3375
authors.initials: Z
authors.lastname: Hens