Abstract
The thermal transformation
in vacuo
of the well defined surface organometallic fragments [AlO]
x
Sn(
n
-C
4
H
9
)
3
(
x
= 1,2) 1 grafted on various partially dehydroxylated aluminas (
α
,
γ
,
η
) has been investigated. The surface reactions were followed by qualitative and quantitative determination of the evolved gases including IR spectroscopy,
13
C cross-polarisation magic angle spinning and
119
Sn magic angle spinning NMR studies. On all aluminas, comparable transformations of 1 were identified showing that the ratio of octahedral: tetrahedral aluminium sites in the aluminas is not an important parameter. Solvolysis reactions of 1 led to the formation of the surface multigrafted species (AlO)
x
+
z
SnBu
3-
z
(
x
= 1, 2;
z
= 1, 2, 3), while
β
-H elimination of but-1-ene followed by reductive elimination led to inorganic tin(
II
) compounds on the surface of the alumina. These transformations occur at temperatures lower than those observed with &z.tbd;SiOSnBu
3
grafted on the surface of silica. This is possibly related to the more acidic properties of alumina or to the higher concentration and/or mobility of Al hydroxy groups with respect to Si hydroxy groups.