TY - JOUR
T1 - Lipidic Mesophase-Embedded Palladium Nanoparticles
T2 - Synthesis and Tunable Catalysts in Suzuki-Miyaura Cross-Coupling Reactions
AU - Duss, Michael
AU - Vallooran, Jijo J.
AU - Salvati Manni, Livia
AU - Kieliger, Nicole
AU - Handschin, Stephan
AU - Mezzenga, Raffaele
AU - Jessen, Henning J.
AU - Landau, Ehud M.
N1 - Funding Information:
The authors thank Dr. Salvatore Assenza for help in figure design, Dr. Chiara Speziale for SAXS measurements, and the Scientific Center for Optical and Electron Microscopy ScopeM of ETH. This work was partially supported by the Forschungskredit (FK-15-083) of the University of Zurich to M.D.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2019/1/8
Y1 - 2019/1/8
N2 - Lipidic cubic phases (LCPs) can reduce Pd 2+ salts to palladium nanoparticles (PdNPs) of ∼5 nm size in their confined water channels under mild conditions. The resulting PdNP-containing LCPs were used as nanoreactor scaffolds to catalyze Suzuki-Miyaura cross-coupling reactions in the aqueous channels of the mesophase. To turn on catalysis, PdNP-containing LCPs were activated by swelling the aqueous channels of the lipidic framework, thereby enabling diffusion of the water-soluble substrates to the catalysts. The mesophases play a threefold role: they act as reducing agents for Pd 2+ , as limiting templates for their growth, and as support. The system was characterized and investigated by small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance. Bulk LCPs and three dispersed palladium/lipid hybrid nanoparticle types were applied in the catalysis. The latter - liposomes, hexosomes, and cubosomes - can be obtained by design through combination of lipids and additives. The Suzuki-Miyaura cross-coupling of 5-iodo-2′-deoxyuridine and phenylboronic acid was used as a model reaction to study these systems. Bulk Pd-LCPs deliver the Suzuki-Miyaura product in 24 h in conversions up to 98% at room temperature, whereas with palladium/lipid dispersions at 40 °C, 68% of the starting material was transformed to the product after 72 h.
AB - Lipidic cubic phases (LCPs) can reduce Pd 2+ salts to palladium nanoparticles (PdNPs) of ∼5 nm size in their confined water channels under mild conditions. The resulting PdNP-containing LCPs were used as nanoreactor scaffolds to catalyze Suzuki-Miyaura cross-coupling reactions in the aqueous channels of the mesophase. To turn on catalysis, PdNP-containing LCPs were activated by swelling the aqueous channels of the lipidic framework, thereby enabling diffusion of the water-soluble substrates to the catalysts. The mesophases play a threefold role: they act as reducing agents for Pd 2+ , as limiting templates for their growth, and as support. The system was characterized and investigated by small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance. Bulk LCPs and three dispersed palladium/lipid hybrid nanoparticle types were applied in the catalysis. The latter - liposomes, hexosomes, and cubosomes - can be obtained by design through combination of lipids and additives. The Suzuki-Miyaura cross-coupling of 5-iodo-2′-deoxyuridine and phenylboronic acid was used as a model reaction to study these systems. Bulk Pd-LCPs deliver the Suzuki-Miyaura product in 24 h in conversions up to 98% at room temperature, whereas with palladium/lipid dispersions at 40 °C, 68% of the starting material was transformed to the product after 72 h.
UR - http://www.scopus.com/inward/record.url?scp=85059698814&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.8b02905
DO - 10.1021/acs.langmuir.8b02905
M3 - Article
C2 - 30517017
AN - SCOPUS:85059698814
SN - 0743-7463
VL - 35
SP - 120
EP - 127
JO - Langmuir
JF - Langmuir
IS - 1
ER -