Liquidꢀcrystalline amphiphilic codendrimers
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 10, October, 2008
2109
The structures of the deposited films were studied by grazing
incidence angle Xꢀray diffraction on an XPERT PRO diffractoꢀ
Dendrimer Gꢀ5ꢀY´OBu(25). The synthesis was carried out
similarly to the procedure for the preparation of compound
Gꢀ3ꢀY´OBu(75) from compound Gꢀ5ꢀ(10ꢀYOH)128 (0.200 g,
0.00292 mmol) and Py (24 mg, 0.280 mmol), which were
dissolved in anhydrous THF (10 mL), and paraꢀbutoxybenzoyl
chloride (63 mg, 0.280 mmol) was added. The product was purified
by preparative GPC. The yield of the chromatographically pure
dendrimer was 138 mg (64%). 1Н NMR (THFꢀd8, 250 MHz), δ:
–0.08 (s, 372 Н); 0.03 (s, 1536 Н); 0.4—0.7 (m, 1264 Н);
1.2—1.4 (m, 2296 Н); 1.67—1.77 (m, 256 Н); 4.05 (t, 64 Н);
4.30 (m, 256 Н); 6.85 (d, 192 Н); 6.95 (d, 64 Н); 7.27 (d, 64 Н);
7.89 (d, 192 Н); 8.06 (d, 64 Н); 8.11 (d, 64 Н).
meter. The range of accessible Q values was 0.07—2.1 Å–1
.
Synthesis of codendrimers. The dendrimers with the phenolic
periphery were synthesized according to a procedure known for
the dendrimers of the first10 and third generations.11,12
1
The Н NMR spectra were similar for all dendrimers (the
only difference being the number of protons) and the assignment
of the signals can be presented as follows, δ: –0.08 (s, Si—CH3
matrix); 0.03 (s, Si—O—Si—CH3); 0.4—0.7 (m, Si—CH2);
1.2—1.4 (m, CH3 of the Bu group); 1.67—1.77 (m, CH2
spacers); 4.05 (t, OCH2 of the Bu group); 4.30 (m, OCH2
of the spacer); 6.85 (d, CH, YOH); 6.95 (d, CH, Y´OBu); 7.27
(d, CH2, YO); 7.89 (d, CH, YOH); 8.06 (d, CH, Y´OBu); 8.11
(d, CH, YO).
Dendrimer Gꢀ3ꢀY´OBu(75). paraꢀButoxybenzoyl chloride
(0.44 mmol, Sigma—Aldrich) was added to a solution of
compound Gꢀ3ꢀ(YOH)32 (0.0178 mmol) (see Scheme 2) and
Et3N (0.44 mmol) in anhydrous THF (10 mL). The reaction
mixture was stirred without cooling for 48 h, then the precipitate
was filtered off, the filtrate was diluted with diethyl ether and
three times washed with water. The organic layer was concenꢀ
trated in vacuo to dryness. The chromatographically pure
dendrimer was isolated by GPC in 58% yield. 1Н NMR (CDCl3,
250 MHz), δ: –0.08 (s, 84 Н); 0.03 (s, 384 Н); 0.4—0.7 (m, 304
Н); 1.2—1.4 (m, 312 Н); 1.67—1.77 (m, 64 Н); 4.05 (t, 48 Н);
4.30 (m, 64 Н); 6.85 (d, 16 Н); 6.95 (d, 48 Н); 7.27 (d, 48 Н);
7.89 (d, 16 Н); 8.06 (d, 48 Н); 8.11 (d, 48 Н).
Dendrimer Gꢀ3ꢀArOBu(50). The synthesis was carried out
similarly to the procedure of the synthesis of compound Gꢀ3ꢀ
ArOBu(75) from Gꢀ3ꢀ(YOH)32 (0.240 g, 0.0142 mmol), Py
(18 mg, 0.228 mmol), and paraꢀbutoxybenzoyl chloride (48 mg,
0.228 mmol). The final purification of the product from
admixtures was carried out by preparative GPC. The yield of the
chromatographically pure dendrimer was 158 mg (56%). 1Н NMR
(CDCl3, 250 MHz), δ: –0.08 (s, 84 Н); 0.03 (s, 384 Н); 0.4—0.7
(m, 304 Н); 1.2—1.4 (m, 568 Н); 1.67—1.77 (m, 64 Н); 4.05
(t, 32 Н); 4.30 (m, 64 Н); 6.85 (d, 32 Н); 6.95 (d, 32 Н); 7.27 (d,
32 Н); 7.89 (d, 32 Н); 8.06 (d, 32 Н); 8.11 (d, 32 Н).
Dendrimer Gꢀ1ꢀY´OBu(75). The synthesis was carried out
similarly to the procedure for the preparation of compound Gꢀ
3ꢀY´OBu(75) from compound Gꢀ1ꢀ(YOH)8 (0.263 g, 0.066
mmol), Py (31.2 mg, 0.396 mmol), and paraꢀbutoxybenzoyl
chloride (84 mg, 0.396 mmol). The product was purified from
admixtures by preparative GPC. The yield of the chromatoꢀ
graphically pure dendrimer was 131 mg (39%). 1Н NMR
(CDCl3, 250 MHz), δ: –0.09 (s, 12 Н); 0.012 (s, 96 Н); 0.55 (m,
64 Н); 1.2—1.4 (m, 136 Н); 1.73 (m, 16 Н); 4.05 (t, 12 Н); 4.27
(m, 16 Н); 6.85 (d, 4 Н); 6.95 (d, 12 Н); 7.27 (d, 12 Н); 7.89 (d,
4 Н); 8.06 (d, 12 Н); 8.11 (d, 12 Н).
Dendrimer Gꢀ5ꢀY´OBu(50). The synthesis was carried out
similarly to the procedure for the preparation of compound Gꢀ
3ꢀY´OBu(75) from compound Gꢀ5ꢀ(YOH)128 (0.130 g, 0.00190
mmol) and Et3N (49.5 mg, 0.490 mmol), which were dissolved
in anhydrous THF (10 mL), and paraꢀbutoxybenzoyl chloride
(24 mg, 0.490 mmol) was added. The product was finally purified
from admixtures by preparative GPC. The yield of the chroꢀ
1
matographically pure dendrimer was 111 mg (74%). Н NMR
(THFꢀd8, 250 MHz), δ: –0.08 (s, 372 Н); 0.03 (s, 1536 Н);
0.4—0.7 (m, 1264 Н); 1.2—1.4 (m, 2296 Н); 1.67—1.77 (m, 256
Н); 4.05 (t, 128 Н); 4.30 (m, 256 Н); 6.85 (d, 128 Н); 6.95 (d,
128 Н); 7.27 (d, 128 Н); 7.89 (d, 128 Н); 8.06 (d, 128 Н); 8.11
(d, 128 Н).
Dendrimer Gꢀ5ꢀY´OBu(75). The reaction mixture conꢀ
sisting of the dendritic carbosilane matrix Gꢀ5ꢀ(CH=CH2)128
(0.100 g, 6.31•10–6 mol), 10ꢀ(1,1,3,3ꢀtetramethyldisiloxanyl)ꢀ
decyl 4ꢀ[(methoxycarbonyl)oxy]benzoate (0.15 g, 0.30•10–3 mol),
4ꢀ{[11ꢀ(1,1,3,3ꢀtetramethyldisiloxanyl)undecyl]oxy}phenyl
4ꢀbutoxybenzoate (0.58 g, 0.91•10–3 mol), a 3% solution (10 μL)
of a Pt complex with divinyltetramethyldisiloxane in xylene
(PCꢀ072), and anhydrous toluene (10 mL) was magnetically
stirred in a closed vessel under argon at 35 °С (in an oil bath) for
72 h. After the cessation of the reaction, the reaction mixture
was passed through silica gel to deactivate the catalyst using
THF as the eluent. Then a 25% aqueous solution of ammonia
(10 mL) was added dropwise on cooling to a solution of the
synthesized compound in an ethanol—THF (1 : 1) system (10 mL).
The reaction mixture was stirred without cooling for 2 h and
then poured into water, and the pH value was brought to 8 with
acetic acid. The resulting suspension was extracted with diethyl
ether three times. The ethereal fraction was washed with water
three times and dried with anhydrous sodium sulfate. The obtained
solution was concentrated in vacuo to dryness. The product was
purified from highꢀmolecularꢀweight admixtures by preparative
GPC. The yield of the chromatographically pure dendrimer was
0.260 g (73%). 1Н NMR (THFꢀd8, 250 MHz), δ: –0.08 (s, 372 Н);
0.03 (s, 1536 Н); 0.4—0.7 (m, 1264 Н); 1.2—1.4 (m, 2296 Н);
1.67—1.77 (m, 256 Н); 4.05 (t, 192 Н); 4.30 (m, 256 Н); 6.85
(d, 64 Н); 6.95 (d, 192 Н); 7.27 (d, 192 Н); 7.89 (d, 64 Н); 8.06
(d, 192 Н); 8.11 (d, 192 Н).
Dendrimer Gꢀ1ꢀY´OBu(50). The synthesis was carried
out similarly to the procedure for the preparation of comꢀ
pound Gꢀ3ꢀY´OBu(75) from compound Gꢀ1ꢀ(YOH)8 (0.100 g,
0.025 mmol), Py (8.1 mg, 0.103 mmol), and paraꢀbutoxybenzoyl
chloride (22 mg, 0.103 mmol). The product was purified from
admixtures by preparative GPC. The yield of the chromatoꢀ
graphically pure dendrimer was 131 mg (39%). 1Н NMR (CDCl3,
250 MHz), δ: –0.09 (s, 12 Н); 0.012 (s, 96 Н); 0.55 (m, 64 Н);
1.2—1.4 (m, 136 Н); 1.73 (m, 16 Н); 4.05 (t, 8 Н); 4.27 (m, 16 Н);
6.85 (d, 8 Н); 6.95 (d, 8 Н); 7.27 (d, 8 Н); 7.89 (d, 8 Н); 8.06 (d,
8 Н); 8.11 (d, 8 Н).
The authors are grateful to A. M. Muzafarov and
E. A. Rebrov (Institute of Synthetic Polymeric Materials,
Russian Academy of Sciences) for the carbosilane denꢀ
drite matrices with terminal allyl groups kindly presented
for the synthesis, as well as to the coworkers of the Instiꢀ
tute of Synthetic Polymeric Materials (Russian Academy
of Sciences) for NMR studies.