12.5.2 T 8
H and Q 8 M 8
H Modified by Other
Oxygen-Containing Groups
Similarly to polysiloxanes (Sect. 12.4.2.2), cubic cage molecules were functionalized with substituents containing hydroxyl, ester, and polyether groups in their
structure via the appropriate hydrosilylation reactions.
Hydroxyaliphatic moieties (Table 12.3, S10 and S11) were introduced to
Q 8 M 8
H by direct hydrosilylation of allyl alcohol [91, 92], 2-allyloxyethanol or
trimethylsiloxyprop-2-ene followed by desilylation of the product via the reaction
with methanol [91]. T 8
H with hydroxyaliphatic substituents (Table 12.3, S10 and
S12) was obtained by hydrosilylation of allyl alcohol or hex-5-ene-1-ol [92].
1 H
NMR spectra showed that in the hydrosilylation of allyl alcohol with Q 8 M 8
H
conducted in toluene Karstedt’s was more active than Speier’s catalyst or
(dichlorodicyclopentadienyl)platinum(II) complex (judged by the rate of disappearance of the Si–H signal); it also gave exclusively the product of C=C
hydrosilylation, whereas in the presence of the other catalysts, significant amounts
of the compound resulting from the so-called O-silylation (dehydrogenative condensation: –OH + H–Si ! –O–Si + H 2 ), with the C=C bond preserved in its
structure, were formed [91]. Spectroscopic studies confirmed that hydrosilylation of
allyl alcohol, trimethylsiloxyprop-2-ene followed by the reaction with methanol and
2-allyloxyethanol with Q 8 M 8
H in toluene in the presence of the proper concentration of Karstedt’s complex, led to the expected cage molecules containing eight
hydroxyaliphatic groups (FTIR: 3339 cm
−1
—OH stretching,
1 H NMR: d =3.76
ppm—OH, d =3.54 ppm—CH 2 –OH,
13 C NMR: d = 65.2 ppm—CH 2 –OH,
29 Si
NMR: d =13.9 ppm, d = −108.3 ppm). Moreover, as corroborated by FTIR,
1 H,
13 C, and
29 Si NMR spectra, product of allyl alcohol hydrosilylation treated with
methacrylolyl chloride transformed to the cage molecules with methacrylate substituents, an UV-curable precursor for polyester nanocomposites [91]. Kim et al.
[92] characterized the materials prepared from Q 8 M 8
H (Karstedt’s catalyst,
1,2-dichloroethane as solvent, reflux) and T 8
H (Speier’s catalyst, 1,2-dichloroethane
as solvent, reflux) by
1 H and
29 Si NMR spectroscopies and blended them with
organic polymers: poly(2-methyl-2-oxazaline), poly(N-vinylpyrrolidone), poly(N,
N-dimethylacrylamide). Existence of hydrogen bonds in the composite systems was
evidenced by the shift in the band due to carbonyl groups of the polymers to lower
wavenumbers in the FTIR spectra of the blends as compared to its position in the
spectra of the polymer matrices [92].
In a series of papers [93–99], a group from Taiwan applied Q 8 M 8
H as a
hydrosilylating agent for 4-acetoxystyrene (Karstedt’s catalyst, toluene, 80 °C).
FTIR spectrum proved that the product (denoted in the work as AS-POSS) contained ester moieties (Table 12.3, S13) (C=O band at 1765 cm
−1 ). Both FTIR and
1 H NMR spectra showed that complete hydrosilylation took place (FTIR: no bands
at 1650 and 2200 cm
−1 ,
1 H NMR: no signals at d = 5.8 and 4.7 ppm). According
to
1 H NMR, hydrosilylation resulted in a mixture of b and a adducts [93].
388
A. Chechelska-Noworyta et al.
H and Q 8 M 8
H Modified by Other
Oxygen-Containing Groups
Similarly to polysiloxanes (Sect. 12.4.2.2), cubic cage molecules were functionalized with substituents containing hydroxyl, ester, and polyether groups in their
structure via the appropriate hydrosilylation reactions.
Hydroxyaliphatic moieties (Table 12.3, S10 and S11) were introduced to
Q 8 M 8
H by direct hydrosilylation of allyl alcohol [91, 92], 2-allyloxyethanol or
trimethylsiloxyprop-2-ene followed by desilylation of the product via the reaction
with methanol [91]. T 8
H with hydroxyaliphatic substituents (Table 12.3, S10 and
S12) was obtained by hydrosilylation of allyl alcohol or hex-5-ene-1-ol [92].
1 H
NMR spectra showed that in the hydrosilylation of allyl alcohol with Q 8 M 8
H
conducted in toluene Karstedt’s was more active than Speier’s catalyst or
(dichlorodicyclopentadienyl)platinum(II) complex (judged by the rate of disappearance of the Si–H signal); it also gave exclusively the product of C=C
hydrosilylation, whereas in the presence of the other catalysts, significant amounts
of the compound resulting from the so-called O-silylation (dehydrogenative condensation: –OH + H–Si ! –O–Si + H 2 ), with the C=C bond preserved in its
structure, were formed [91]. Spectroscopic studies confirmed that hydrosilylation of
allyl alcohol, trimethylsiloxyprop-2-ene followed by the reaction with methanol and
2-allyloxyethanol with Q 8 M 8
H in toluene in the presence of the proper concentration of Karstedt’s complex, led to the expected cage molecules containing eight
hydroxyaliphatic groups (FTIR: 3339 cm
−1
—OH stretching,
1 H NMR: d =3.76
ppm—OH, d =3.54 ppm—CH 2 –OH,
13 C NMR: d = 65.2 ppm—CH 2 –OH,
29 Si
NMR: d =13.9 ppm, d = −108.3 ppm). Moreover, as corroborated by FTIR,
1 H,
13 C, and
29 Si NMR spectra, product of allyl alcohol hydrosilylation treated with
methacrylolyl chloride transformed to the cage molecules with methacrylate substituents, an UV-curable precursor for polyester nanocomposites [91]. Kim et al.
[92] characterized the materials prepared from Q 8 M 8
H (Karstedt’s catalyst,
1,2-dichloroethane as solvent, reflux) and T 8
H (Speier’s catalyst, 1,2-dichloroethane
as solvent, reflux) by
1 H and
29 Si NMR spectroscopies and blended them with
organic polymers: poly(2-methyl-2-oxazaline), poly(N-vinylpyrrolidone), poly(N,
N-dimethylacrylamide). Existence of hydrogen bonds in the composite systems was
evidenced by the shift in the band due to carbonyl groups of the polymers to lower
wavenumbers in the FTIR spectra of the blends as compared to its position in the
spectra of the polymer matrices [92].
In a series of papers [93–99], a group from Taiwan applied Q 8 M 8
H as a
hydrosilylating agent for 4-acetoxystyrene (Karstedt’s catalyst, toluene, 80 °C).
FTIR spectrum proved that the product (denoted in the work as AS-POSS) contained ester moieties (Table 12.3, S13) (C=O band at 1765 cm
−1 ). Both FTIR and
1 H NMR spectra showed that complete hydrosilylation took place (FTIR: no bands
at 1650 and 2200 cm
−1 ,
1 H NMR: no signals at d = 5.8 and 4.7 ppm). According
to
1 H NMR, hydrosilylation resulted in a mixture of b and a adducts [93].
388
A. Chechelska-Noworyta et al.