Chemistry Reference
In-Depth Information
It has recently been demonstrated that ADMET occurs in the solid state. If the
ADMET of 1,9-decadiene is carried out at temperatures below 60
C, the polyocte-
namer will solidify after an average DP of about 5 is reached. Using the carrier
gas method, ADMET continues in this solid for days as proven by GPC analysis.
In some cases molecular weights of greater than 70 kDa with complex
10
have
been observed by this method. It is not a general method, however, and the scope
and limitations are still being explored [106].
6.8
Conclusions and Outlook
In conclusion, the expanded scope of ADMET is largely due to the development
of well-defined late-transition metal catalysts that are functional group-tolerant
and easy to handle and synthesize. The potential for ADMET is very great, in that
it is a mild method of forming useful linear condensation polymers and copoly-
mers. The application of ADMET in modeling polyolefins and other polymers is
just being discovered, and this aspect of ADMET is expected to further the under-
standing of these enormously important polymers.
Catalyst synthesis is also progressing at a rapid rate, which will allow ADMET
to be carried out under even simpler conditions and with more and more func-
tionalized monomers. New catalysts that display both higher activity and higher
stability represent significant advances in catalyst design. Many potentially AD-
MET-active complexes were not discussed in this chapter, simply because they
have not been used in ADMET chemistry. These include, among others, the styre-
nyl ether-based complexes developed by Hoveyda [98, 107] and two classes of cata-
lysts developed by Grubbs: bimetallic complexes [108] and salicylaldimine-ligated
ruthenium complexes [109]. Metathesis polymerization in general is expected to
be an enormously important field of active research and development in the fu-
ture, both academically and industrially, which has and will attract many talented
young minds.
6.9
References
Ivin, K. J., Mol, J.C., Olefin Metathesis
and Metathesis Polymerization, Aca-
demic Press, San Diego, CA 1997.
5
Phillips, A. J., Abell, A.D.,
Aldrichim.
Acta
1999
, 32, 75-89.
6
Wright, D. L. Curr. Org. Chem.
1999
,3,
211-240.
1
Maier, M. E.
Angew. Chem. Int. Ed. Eng.
2000
,
39
, 2073-2077.
2
Randall, M. L., Snapper, M. L.,
J. Mol.
Cat. A
1998
,
133
, 29-40.
7
Roy, R., Das, S.K.,
Chem. Commun.
2000
,
519-529.
3
8
Ivin, K. J.,
J. Mol. Cat. A
1998
,
133
, 1-16.
4
Buchmeiser, M.R .,
Chem. Rev.
2000
,
100
, 1565-1604.
9
Grubbs, R.H., Chang, S.,
Tetrahedron
1998
,
54
, 4413-4450.
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