H. Frey et al.
4.56 (t, J=1.47 Hz, 2H, h-C5H4), 4.39 (t, J=1.47 Hz, 2H, h-C5H4),
4.28 ppm (s, 5H, h-C5H5).
(1 mL), and stirred in the presence of an excess of active charcoal to
bind most of the platinum. The solution was filtered over Celite to
remove charcoal, concentrated in vacuo, and precipitated into MeOH.
After drying in vacuo the mixture of hyperbranched homopolymer and
the desired block copolymer was purified by 1) dialysis in THF using a
dialysis tube with a molecular weight cutoff of ca. 8 kgmolÀ1 to remove
the hbPCS; or by 2) repetitive precipitation into hexanes to remove the
hexane-soluble hbPCS (only applicable for block copolymers with a low
DPn of the hypergrafted hbPCS); or by 3) preparative SEC in THF to
remove all low molecular weight material. Yields varied between 40 and
90%. For molecular weight data for 9–19, see Table 1.
Diallylferrocenylsilane (3): A solution of dichloroferrocenylsilane (3a)
(6.00 g, 21 mmol) in dry diethyl ether (10 mL) was added slowly to a
freshly prepared solution (90 mL) of allylmagnesium bromide (0.9m;
81 mmol) in diethyl ether. To complete the reaction the mixture was
stirred for 12 h at reflux. At 08C a saturated solution (10 mL) of NH4Cl
was added, followed by H2O (15 mL). The organic layer was separated
and washed twice with a saturated Na2CO3 solution. The diethyl ether
layer was washed with water until the aqueous layer gave a neutral reac-
tion. The organic layer was dried with MgSO4. The crude product (5.9 g)
obtained by removal of the solvent was purified by column chromatogra-
NMR characterization for block copolymers based on 1: 1H NMR
(300 MHz, C6D6): 5.85 (m, CH=CH2), 4.98 (m, CH=CH2), 4.31–4.00 (br,
m, Cp), 1.83–1.31 (br, m, SiCH2), 1.10–0.62 (br, m, SiCH2), 0.54 (s, SiMe
(PFS)), 0.24–0.01 ppm (br, m, SiMe (PCS)); 13C NMR (100.15 MHz,
phy (silica, petroleum ether, Rf =0.22). Yield: 4.6 g (74%) of a red oil;
1
À
H NMR (300 MHz, CDCl3): d=5.92 (m, 2H, CH=CH2), 5.09–4.85 (m,
À
À
4H, CH=CH2), 4.38 (m, 2H, h-C5H4), 4.32 (m, 1H, Si H), 4.19 (m, 2H,
h-C5H4), 4.17 (s, 5H, h-C5H5), 1.91–1.81 ppm (m, 4H, CH2); 13C NMR
C6D6): d=134.9 ACTHNUGTRNENUG(linear), 134.5 (terminal) (CH=CH2), 113.1 ACHTUNGTRENNUNG(linear),
112.8 (terminal) (CH=CH2), 73.5–71.0 (Cp), 21.9–18.0 (different CH2),
À1.0 (SiMe2 (PFS)), À4 to À6.4 ppm (different SiMe); 29Si NMR
(79.49 MHz, C6D6): d=1.2 (dendritic PCS), 0.8 (linear PCS), 0.2 (termi-
nal PCS), À3.5 (SiMe (PFS)), À6.5 ppm (SiMe2 (PFS)).
À
À
(75 MHz, CDCl3): d=134.56 ( CH=CH2), 114.05 ( CH=CH2), 73.75 (h-
C5H4(CH)), 71.13 (h-C5H4(CH)), 68.51 (h- C5H5), 64.57 (h-C5H4(C),
19.84 ppm (CH2); 29Si-NMR (60 MHz, CDCl3): d=À4.20 ppm; IR n˜ =
À
À
3075 (stretching C H), 2954, 2922, 2853 (stretching C H), 2117 (stretch-
ing Si H), 1630 cm (stretching C=C); FDMS: m/z: calcd (%) for
C16H20FeSi: 296.3; found: 295.9. elemental analysis: calcd (%) for
C16H20FeSi: C 64.87, H 6.80; found: C 64.85, H 6.80.
À1
NMR characterization for block copolymers based on 2: 1H NMR
(300 MHz, C6D6): d=5.85 (br, m, CH=CH2), 5.10 (br, m, CH=CH2),
4.31–4.00 (br, m, Cp), 2.06 (br, CH2), 1.83–1.31 (br, m, SiCH2), 1.40 (br,
CH2), 0.70–0.56 (br, SiMe (PFS)), 0.18 (br, SiMe (PCS directly bound to
PFS)), 0.10 ppm (br, SiMe (PCS periphery)); 13C NMR (100.15 MHz,
C6D6): d=134.9, 134.5 (CH=CH2), 113.1, 112.8 (CH=CH2), 73.5–71.0
(Cp), 21.9–18.0 (different CH2), À1.0 (SiMe2 (PFS)), À4.2 ppm (different
SiMe).
À
Dimethyl[1]silaferrocenophane (4): Over
a
5 min period, Me2SiCl2
suspension of
(4.6 mL, 38 mmol) was added dropwise to
a
fcLi2·2= TMEDA (10.0 g, 36.4 mmol) in diethyl ether (500 mL) at À608C.
3
The reaction mixture was then allowed to warm slowly to 208C over 4 h,
during which the reaction mixture changed from orange-yellow to red.
The solvent and excess Me2SiCl2 were removed in vacuo. The crude
product was redissolved in dry hexane, filtered, and concentrated in
vacuo. Crystallization of the crude product from hexanes (À208C) and
repetitive sublimation (ꢄ3, 0.005 mmHg) at room temperature onto a
cold probe afforded red crystalline [1]ferrocenophane 4 (6.98 g, 79%).
1H NMR (300 MHz,C6D6): d=0.51 (s, 6H, Me), 4.08 (t, JHÀH =1.7 Hz,
4H, Cp), 4.48 ppm (t, JHÀH =1.7 Hz, 4H, Cp).
NMR characterization for block copolymers based on 3: 1H NMR
(300 MHz, C6D6): d=6.04 (m, CH=CH2), 5.14 (m, CH=CH2), 4.35–4.01
(br, m, Cp), 1.96–0.92 (br, m, SiCH2), 0.55 (s, SiMe2 (PFS)), 0.28 ppm (s,
SiMe (PFS)); 13C NMR (100.15 MHz, C6D6) d=135.3 (linear), 134.9 (ter-
minal) (CH=CH2), 113.5 (linear), 113.2 (terminal) (CH=CH2), 73.5–71.0
(Cp (PFS)), 70.7, 68.2 (br, Cp (PCS)), 21.9–18.0 (different CH2), 0.9
(SiMe (PFS), À1.0 ppm (SiMe2 (PFS)); 29Si NMR (79.49 MHz, C6D6): d=
À2.6 (dendritic PCS), À3.6 (linear PCS), À4.6 (terminal PCS), À6.5
(SiMe2 (PFS)), À21.5 ppm (SiMe (PFS)).
Preparation of TEM samples: Block copolymer (1 mg) was dissolved in
THF (50 mL). Then decane was added dropwise to the mixture to give a
decane/THF (9:1) mixture . The opaque solutions were allowed to stabi-
lize for 12 h, then drop-cast onto copper TEM grids and dried overnight
to remove the solvents.
Methylvinyl[1]silaferrocenophane (5): Synthesis and purification were
analogous to the methods used for 4, but with (CH2=CH)MeSiCl2
(4.97 mL, 38 mmol) as the respective silane instead of Me2Cl2,. Yield:
6.5 g (70%); 1H NMR (300 MHz,C6D6): d=0.61 (s, 3H, Me), 4.08 (t,
JHÀH =1.7 Hz, 4H, Cp), 4.48 (t, JHÀH =1.7 Hz, 4H, Cp), 5.98 (dd, 2H, J=
20 Hz, J=80 Hz), 6.54 ppm (t, 1H, J=16 Hz).
General procedure for photocontrolled polymerization of 4 and 5: In an
inert atmosphere glove box a Schlenk tube was charged with 4 (500 mg,
2.06 mmol) dissolved in THF (ca. 4 mL) and a THF solution (21 mL) of
Sonification was conducted over a period of 30 min at room temperature,
then a solution (50 mL) of a unimer (ca. 1 gLÀ1 in THF) was added to the
mixture and allowed to equilibrate over a period of 5 h. The sample was
drop-cast onto a copper grid and dried in vacuo overnight.
NaACHTUNGTRENNUNG[C5H5] (1m, 0.021 mmol) was added to the dark red solution in the ab-
sence of light. The mixture was photolyzed for 4 h at 58C. The reaction
vessel containing an orange solution was introduced into the glove box
and the calculated amount of 5 (160 mg, 0.63 mmol for sample 8, Table 1)
was added in the absence of light. Photolysis was continued for 2 h and
the reaction was quenched with 10 drops of freshly distilled Me3SiCl. The
solvents were removed in vacuo to give an orange film, which was redis-
solved in THF and precipitated into MeOH to give an orange powder
that was dried in vacuo at 408C for 48 h and stored under argon at 58C.
For molecular weight data for 6–8, see Table 1; 1H NMR (300 MHz,
C6D6): d=6.54 (t, J=16 Hz), 5.98 (dd, J=20 Hz, J=80 Hz), 4.31–4.00
(br, m, Cp), 0.62 (s), 0.54 ppm (s); 13C NMR (100.15 MHz, C6D6): d=
Acknowledgements
The authors thank Ian Manners for hosting a visit of F.W. to his labs at
the University of Bristol to facilitate synthesis of the poly(ferrocenylsi-
lane) block copolymers. We also thank Dr. George Whittell and Dr.
Torben Gaedt in the Manners’ group for helpful discussions. The authors
thank Margarete Deptolla for her technical assistance. H.F. acknowledges
the Fonds der Chemischen Industrie (FCI) for valuable financial support.
F.W. and S.H. thank “POLYMAT” in the Graduate School of Excellence
(MAINZ) for funding.
À
À
137.9 (Si CH=CH2), 132.2 (Si CH=CH2), 73.5–71.3 (Cp), À1.0 (SiMe2),
À3.3 ppm (SiMeVi); 29Si NMR (79.49 MHz, C6D6): d=À6.5 (SiMe2),
À13.0 ppm (SiMeVi).
General procedure for hypergrafting of AB2 monomers (1, 2, 3) to linear
PFS block copolymers (6, 7, 8): The polymer core (100 mg) was placed in
a Schlenk tube under argon. The polymer was dissolved in dry chloroben-
zene (ca. 200 mL) and the calculated amount of AB2 monomer was
added. The mixture was heated to 608C and Karstedt’s catalyst (2.4% in
xylene, 2 mL (0.25 mmol Pt)) was added to start the reaction. The tube
was closed by means of a Teflon tap and hydrosilylation was continued
for ca. 10 h (until the Si–H vibration (at ca. 2100 cmÀ1) was absent from
the IR spectrum). The sludge was diluted with THF (5 mL) and MeOH
[1] a) R. D. Archer, Inorganic and Organometallic Polymers, Wiley,
[2] a) C. Simionescu, T. Lixandru, I. Negulescu, I. Mazilu, L. Tataru,
9076
ꢂ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 9068 – 9077