| Autor: |
Calvin JJ; Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., Sedlak AB, Brewer AS; Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States., Kaufman TM, Alivisatos AP; Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.; Kavli Energy NanoScience Institute, Berkeley, California 94720, United States. |
| Jazyk: |
angličtina |
| Zdroj: |
ACS nano [ACS Nano] 2024 Sep 10; Vol. 18 (36), pp. 25257-25270. Date of Electronic Publication: 2024 Aug 26. |
| DOI: |
10.1021/acsnano.4c08439 |
| Abstrakt: |
As synthesized, nanocrystal surfaces are typically covered in coordinating organic ligands, and the degree of packing and order of these ligands are ongoing questions in the field of colloidal nanocrystals, particularly in the solution state. Recently, isothermal titration calorimetry coupled with 1 H NMR has been used to probe ligand exchanges on colloidal quantum dots, revealing the importance of the composition of the ligand shell on exchange thermodynamics. Previous work has shown that the geometry and length of a ligand's aliphatic chain can influence the thermodynamics of exchange. This has been attributed to interligand interactions, and the use of a modified Ising model simulation to account for these collective effects has been critical in describing these reactions. In this report, we explore the reaction between indium phosphide quantum dots and zinc chloride on a size series of nanocrystals capped with two different lengths of aliphatic, straight-chain carboxylate ligands to investigate the effect that nanocrystal size has on these interligand interactions. We demonstrate that interligand interactions increase as the nanocrystal size increases, changing the thermodynamics of the ligand exchange reaction. Critically, we show that a self-consistent model of these ligand exchanges does not fit the data without the use of a phase transition term in the model and that the strength of this phase transition depends on the nanocrystal size. Combined with solution state X-ray diffraction, these results provide indirect evidence that ligands are ordered on nanocrystals in the solution state. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
