TY - JOUR
T1 - β-Cyclodextrin-Silica Hybrid
T2 - A Spatially Controllable Anchoring Strategy for Cu(II)/Cu(I) Complex Immobilization
AU - Calsolaro, Federica
AU - Martina, Katia
AU - Borfecchia, Elisa
AU - Chávez-Rivas, Fernando
AU - Cravotto, Giancarlo
AU - Berlier, Gloria
N1 - Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/10
Y1 - 2020/10
N2 - The development of new strategies for spatially controllable immobilization has encouraged the preparation of novel catalysts based on the organic-inorganic hybrid concept. In the present paper, a Cu-based multi-structured silica catalyst has been prepared and fully characterized. The inclusion of Cu(II) in β-cyclodextrins has been exploited with the double aim to stabilize the metal and to act as a source of Cu(I) catalytic sites. Multi-technique characterization by infrared, UV-visible, electron microscopy and X-ray absorption spectroscopies of the fresh and exhaust catalysts provided information on the local structure, redox properties and stability of the investigated hybrid systems. The catalytic system showed that copper nanospecies were dispersed on the support and hardly affected by the catalytic tests, confirming the stabilizing effect of β-CD, and likely of the N1-(3-Trimethoxysilylpropyl) diethylenetriamine spacer, as deduced by X-ray absorption spectroscopy analysis. Overall, we demonstrate a feasible approach to efficiently anchor Cu(II) species and to obtain a reusable single-site hybrid catalyst well suited for Cu(I)-catalyzed alkyne-azide cycloaddition.
AB - The development of new strategies for spatially controllable immobilization has encouraged the preparation of novel catalysts based on the organic-inorganic hybrid concept. In the present paper, a Cu-based multi-structured silica catalyst has been prepared and fully characterized. The inclusion of Cu(II) in β-cyclodextrins has been exploited with the double aim to stabilize the metal and to act as a source of Cu(I) catalytic sites. Multi-technique characterization by infrared, UV-visible, electron microscopy and X-ray absorption spectroscopies of the fresh and exhaust catalysts provided information on the local structure, redox properties and stability of the investigated hybrid systems. The catalytic system showed that copper nanospecies were dispersed on the support and hardly affected by the catalytic tests, confirming the stabilizing effect of β-CD, and likely of the N1-(3-Trimethoxysilylpropyl) diethylenetriamine spacer, as deduced by X-ray absorption spectroscopy analysis. Overall, we demonstrate a feasible approach to efficiently anchor Cu(II) species and to obtain a reusable single-site hybrid catalyst well suited for Cu(I)-catalyzed alkyne-azide cycloaddition.
KW - Copper-catalysis
KW - Diffuse reflectance UV-visible
KW - Green chemistry
KW - Infrared spectroscopy
KW - Organic-inorganic hybrid material
KW - Silica
KW - X-ray absorption spectroscopy
KW - β-cyclodextrin
UR - http://www.scopus.com/inward/record.url?scp=85091649716&partnerID=8YFLogxK
U2 - 10.3390/catal10101118
DO - 10.3390/catal10101118
M3 - Artículo
AN - SCOPUS:85091649716
SN - 2073-4344
VL - 10
SP - 1
EP - 16
JO - Catalysts
JF - Catalysts
IS - 10
M1 - 1118
ER -