Table 7 Summarized morphological features of the materials obtained
from XRD and nitrogen sorption experiments
obtained materials displayed high porosity even with high
content of the ionic substructure, due to the high degree of
molecular rigidity of the ionic precursor. However, in the case of
the materials containing high degrees of organic parts and,
consequently, low silica content, the structural regularity
decreased.
Interpore
distance
Average pore
a
ꢂ
Estimated wall
ꢂ
thickness/A
Material
diameter/A
A1/2
A1/3
A1/4
A1/6
A1/9
129
144
131
121
127
40
55
54
72
60
89
89
77
49
67
The reported materials are versatile precursors for the gener-
ation of silica hybrid supported N-heterocyclic carbene
complexes and have large potential for the elaboration of recy-
clable heterogeneous catalysts. We are currently investigating
these materials for applications in Pd-catalyzed C–C cross
coupling reactions. These results will be reported in due course.
a
Average pore sizes were calculated from the adsorption branch of the
nitrogen sorption isotherm.
Acknowledgements
The authors gratefully acknowledge Eva Rettenmeier for tech-
nical assistance. P. Hesemann thanks the ‘Groupement de
ꢁ
Recherche PARIS’ and the ‘Reseau de Recherche 3, Chimie pour
ꢁ
le Developpement Durable ’ of the CNRS for financial support.
Fig. 6 TEM micrographs of materials A1/9 (left/middle) and A1/3
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This journal is ª The Royal Society of Chemistry 2009