Biomedical Engineering Reference
In-Depth Information
Figure 7.3
XRD patterns of the product from PTHF (a) and amylose (b).
1
of the product showed
signals owing to not only amylose but also PTHF (Fig. 7.4), in
spite of washing with methanol, which is a good solvent of PTHF.
Furthermore, the methylene peak of PTHF was broadened and
shifted upfield compared to that of the original PTHF. This is
The
H NMR spectrum in DMSO-
d
6
because each methylene group of PTHF is immobile and interacts
with the protons inside the amylose cavity. When PTHF was added to
the NMR sample of the product in DMSO-
, two different signals due
to methylene protons of PTHF were observed. This result suggested
that the PTHF of the product was in an environment different from an
original PTHF unit. To further confirm the structure of the product,
spin-lattice relaxation time (
d
6
T
) measurements were investigated,
1
as
measurements of inclusion complexes have often been used
for the identification of their structures. In general, the
T
1
values of
the inclusion complexes are shorter than those of the corresponding
individual molecules. Actually, the
T
1
value of the methylene peak of
the PTHF in the product was shorter than that of the original PTHF.
The shorter
T
1
in the product indicated restriction of the methylene
movement due to the included conditions.
T
1
