166
10 Metallo-Carbohedrenes and Their Reactivity
Fig. 10.2 Mass spectra of products arising from reactions of Ti 8 C 12
+ with methanol obtained
at a very low partial pressure of methanol (a), and a much higher pressure of methanol (b). The
number stands for the number of methanol molecules associating onto Ti 8 C 12
+ . Note that association
reactions terminate at the eighth step. Mass spectra of products arising from reactions of Ti 8 C 12
+
with benzene: c obtained at a very low partial pressure of benzene; d obtained at a much higher
partial pressure of benzene. The number stands for the number of benzenes associating onto Ti 8 C 12
+ .
Note that association reactions terminate at the fourth step. Reproduced with permission from Ref.
[65]. Copyright 1993 American Chemical Society
indicating the distinctive stability of Ti 8 C 12
+ (CH 3 OH) 8 with fully occupied Ti atom
sites.
Reaction of Ti 8 C 12
+ with benzene was found to produce Ti 8 C 12
+ (C 6 H 6 ) x with a
limitation of x up to 4 indicating the association reactions terminate at the fourth step
for Ti 8 C 12
+ encountering with benzene molecules. The Ti 8 C 12
+ (C 6 H 6 ) 4 was found
to dominate the observed products and appear as the only one product surviving in
the presence of large quantity of benzene. In view of the unique geometry of Ti 8 C 12
+
by possessing 12-faces and each face having three carbon atoms and two Ti atoms,
it is reasonable for the benzene ring to be flat-adsorption on the four nonadjacent
faces ascribed to the delocalized π-electrons of benzene. The reactivity of Ti 8 C 12
+
with four benzene molecules was expressed as,
Ti 8 C
+
12 + 4C 6 H 6 → Ti 8 C
+
12 (C 6 H 6 ) 4
(10.3)
Note that all these reactions involved only an association mechanism but no
evidence for destructive eliminations to the Met-Cars due to their decent stability.
Some further investigations have further eliminated the association reactivity of
Ti 8 C 12
+ with the polar molecule systems. In particular, the association reactions were
10 Metallo-Carbohedrenes and Their Reactivity
Fig. 10.2 Mass spectra of products arising from reactions of Ti 8 C 12
+ with methanol obtained
at a very low partial pressure of methanol (a), and a much higher pressure of methanol (b). The
number stands for the number of methanol molecules associating onto Ti 8 C 12
+ . Note that association
reactions terminate at the eighth step. Mass spectra of products arising from reactions of Ti 8 C 12
+
with benzene: c obtained at a very low partial pressure of benzene; d obtained at a much higher
partial pressure of benzene. The number stands for the number of benzenes associating onto Ti 8 C 12
+ .
Note that association reactions terminate at the fourth step. Reproduced with permission from Ref.
[65]. Copyright 1993 American Chemical Society
indicating the distinctive stability of Ti 8 C 12
+ (CH 3 OH) 8 with fully occupied Ti atom
sites.
Reaction of Ti 8 C 12
+ with benzene was found to produce Ti 8 C 12
+ (C 6 H 6 ) x with a
limitation of x up to 4 indicating the association reactions terminate at the fourth step
for Ti 8 C 12
+ encountering with benzene molecules. The Ti 8 C 12
+ (C 6 H 6 ) 4 was found
to dominate the observed products and appear as the only one product surviving in
the presence of large quantity of benzene. In view of the unique geometry of Ti 8 C 12
+
by possessing 12-faces and each face having three carbon atoms and two Ti atoms,
it is reasonable for the benzene ring to be flat-adsorption on the four nonadjacent
faces ascribed to the delocalized π-electrons of benzene. The reactivity of Ti 8 C 12
+
with four benzene molecules was expressed as,
Ti 8 C
+
12 + 4C 6 H 6 → Ti 8 C
+
12 (C 6 H 6 ) 4
(10.3)
Note that all these reactions involved only an association mechanism but no
evidence for destructive eliminations to the Met-Cars due to their decent stability.
Some further investigations have further eliminated the association reactivity of
Ti 8 C 12
+ with the polar molecule systems. In particular, the association reactions were