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Carboxylic‐Acid‐Passivated Metal Oxide Nanocrystals: Ligand Exchange Characteristics of a New Binding Motif
Author(s) -
De Roo Jonathan,
Justo Yolanda,
De Keukeleere Katrien,
Van den Broeck Freya,
Martins José C.,
Van Driessche Isabel,
Hens Zeger
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201500965
Subject(s) - chemistry , carboxylate , oxide , adsorption , steric effects , carboxylic acid , inorganic chemistry , ligand (biochemistry) , metal , sulfide , polymer chemistry , stereochemistry , organic chemistry , biochemistry , receptor
Ligand exchange is central in the processing of inorganic nanocrystals (NCs) and requires understanding of surface chemistry. Studying sterically stabilized HfO 2 and ZrO 2 NCs using 1 H solution NMR and IR spectroscopy as well as elemental analysis, this paper demonstrates the reversible exchange of initial oleic acid ligands for octylamine and self‐adsorption of oleic acid at NC surfaces. Both processes are incompatible with an X‐type binding motif of carboxylic acids as reported for sulfide and selenide NCs. We argue that this behavior stems from the dissociative adsorption of carboxylic acids at the oxide surface. Both proton and carboxylate moieties must be regarded as X‐type ligands yielding a combined X 2 binding motif that allows for self‐adsorption and exchange for L‐type ligands.