Chemistry Reference
In-Depth Information
the wear effects. With respect to organic syntheses in PBMs this parameter has
been evaluated for various reaction examples such as Suzuki cross-coupling
(Scheme 10.2),
72
oxidative homo-coupling,
62,63
as well as the oxidation of
g-terpinene to p-cymene
77
and of b-pinene to nopinone (Scheme 10.3A-B).
73
The correlations between product yield and n
MB
for reactions carried out in a
PBM with d
MB
¼
15 mm are shown in summarized in Figure 10.7.
The results indicate a strong linear relationship between those two vari-
ables, which is reasonable since Eq. (10.1) proves the direct proportionality
of E
kin
and the mass of the moving grinding bodies. While the number of
grinding bodies in the milling vial increases the transferred energy is higher
KMnO
4
, H
2
O
alumina
O
A
planetary ball mill
MV, MB = MSZ
KMnO
4
, H
2
O
alumina
B
planetary ball mill
MV, MB = MSZ
KMnO
4
neutral
γ
-Al
2
O
3
N
C
NH
2
N
planetary ball mill
MV, MB = agate
Scheme 10.3 Oxidative model reactions used for the investigation of parameter
effects.
Figure 10.7 Correlation of product yield with the number of milling balls n
MB
for
several model reactions in a PBM. (For references to the individual data
see the text.)
Search WWH ::
Custom Search