Mixed-Monolayer-Protected Au25 Clusters with Bulky Calix[4]arene Functionalities.
Although various complex, bulky ligands have been used to functionalize plasmonic gold nanoparticles, introducing them to small, atomically precise gold clusters is not trivial. Here, we demonstrate a simple one-pot procedure to synthesize fluorescent magic number Au25 clusters carrying controlled amounts of bulky calix[4]arene functionalities. These clusters are obtained from a synthesis feed containing binary mixtures of tetrathiolated calix[4]arene and 1-butanethiol. By systematic variation of the molar ratio of ligands, clusters carrying one to eight calixarene moieties were obtained. Structural characterization reveals unexpected binding of the calix[4]arenes to the Au25 cluster surface with two or four thiolates per moiety.
†Department of Applied Physics, Aalto University (Helsinki University of Technology), Puumiehenkuja 2, FI-02150 Espoo, Finland.
Jukka
J
Hassinen
‡Department of Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland.
Petri
P
Pulkkinen
Elina
E
Kalenius
⊥DST Unit of Nanoscience (DST UNS), Department of Chemistry, Indian Institute of Technology, Madras, Chennai 600 036, India.
Thalappil
T
Pradeep
‡Department of Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland.
Heikki
H
Tenhu
Hannu
H
Häkkinen
†Department of Applied Physics, Aalto University (Helsinki University of Technology), Puumiehenkuja 2, FI-02150 Espoo, Finland.
Robin H A
RH
Ras
calixarene; clusters; functionalization; gold