Synthesis of Conjugated Main-Chain Ferrocene-Containing Polymers through Melt-State Polymerization

Article abstract of DOI:10.1021/acs.organomet.9b00312

Two kinds of conjugated main-chain ferrocene (Fc)-containing polymers, PFcT8 and PFcTP8, were successfully prepared through the facile melt-state polymerization (MSP) of corresponding monomers which combine the Fc motif with thiophene or thiophene-methane groups. The simple, low-cost MSP was chosen as the method, while thiophene or thiophene-methane groups served as reactive sites for its feature of easy polymerization by a simple heating process. The prepared metallopolymers were characterized by ¹H NMR, FTIR, and photochemical and electrochemical analysis, metal content, and thermal stability. The results show that metallopolymers with a regular backbone and nearly quantitative metal content were obtained. In addition, the metallopolymer PFcTP8 has the smallest optical band gap (absorption edge at 1100 nm) and high thermal stability among reported Fc-containing polymers, which indicates the thiophene-methane-based Fc-containing structure is a good candidate to construct functional polymers through MSP. The low band gap and high thermal stability of prepared conjugated metallopolymers show their potential application in conducting materials with high working temperature.

Full text of DOI:10.1021/acs.organomet.9b00312

Article
pubs.acs.org/Organometallics
Cite This: Organometallics XXXX, XXX, XXX−XXX
Synthesis of Conjugated Main-Chain Ferrocene-Containing
Polymers through Melt-State Polymerization
Qi Luo,† Rui Zhang,† Jing Zhang,*,† and Jiangbin Xia*,†,‡
†Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, College of Chemistry and Molecular Sciences, Wuhan
University, Wuhan 430072, People’s Republic of China
‡Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and
Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
S
* Supporting Information
ABSTRACT: Two kinds of conjugated main-chain ferrocene
(Fc)-containing polymers, PFcT8 and PFcTP8, were
successfully prepared through the facile melt-state polymer-
ization (MSP) of corresponding monomers which combine
the Fc motif with thiophene or thiophene-methane groups.
The simple, low-cost MSP was chosen as the method, while
thiophene or thiophene-methane groups served as reactive sites for its feature of easy polymerization by a simple heating
process. The prepared metallopolymers were characterized by 1H NMR, FTIR, and photochemical and electrochemical analysis,
metal content, and thermal stability. The results show that metallopolymers with a regular backbone and nearly quantitative
metal content were obtained. In addition, the metallopolymer PFcTP8 has the smallest optical band gap (absorption edge at
1100 nm) and high thermal stability among reported Fc-containing polymers, which indicates the thiophene-methane-based Fc-
containing structure is a good candidate to construct functional polymers through MSP. The low band gap and high thermal
stability of prepared conjugated metallopolymers show their potential application in conducting materials with high working
temperature.
out in various substrates such as the surface of mesoporous
silica,32 organic particles,33 and cellulose fibers.34
1. INTRODUCTION
Ferrocene (Fc)-containing polymers have been widely applied
in many areas, such as gas storage,1,2 magnetic materials,3,4
organic electronics,5−7 catalysis,8,9 sensors,10−13 etc., due to
their unique sandwich structure and intriguing properties of
the Fc group. For example, Fromm et al. have recently
reported a mechanically induced metal ion release polymer
where Fc was incorporated as an iron ion releasing
mechanophore that responds to sonication.14 Various synthetic
pathways, including living and controlled polymerization
strategies as well as surface immobilization methodologies,15,16
have been developed to prepare main-chain17 and side-
chain18−20 Fc-containing polymers. Poly(vinylferrocene) was
the first Fc-containing polymer and was synthesized through
free radical polymerization by Arimoto and co-workers in the
1950s.21 During the next decades, several controlled and living
polymerization methodologies, including the anionic polymer-
ization of vinylferrocene22,23 and ring-opening polymerization
of norbornene derivatives24 or strained ferrcoenophanes,25
have emerged and enriched the scope of Fc-containing
polymers. In order to prepare metallopolymers with a specific
morphology or application, some novel methods, including
surface-initiated polymerization for surface-decorated Fc-
containing polymers,26 an electrostatic layer-by-layer (LbL)
deposition technique for functional multilayer polymer films,27
and self-assembly for nanoparticles28,29 or (hydro)gels,30,31
have also been developed. For instance, the surface-initiated
polymerization of Fc-containing methacrylates can be carried
Synthesis of main-chain Fc-containing polymers, in which
the Fc motif is integrated into the polymer backbone, is a big
challenge due to the necessity of constructing a difunctional-
ized Fc group in the monomer synthesis step. Moreover, in
addition to poly(ferrocenylenevinylene)35,36 and polyferroce-
nylenes,37 there are few reports about conjugated Fc-
containing polymers that integrate the Fc into the main
chain.38,39 Choi and co-workers7 have prepared a redox-active
main-chain Fc-containing polymer through the palladium-
catalyzed copolymerization of three different components.
However, in terms of structure, this method may lead to an
irregular structure and poor experimental reproducibility. On
the basis of the above research as well as our recent proposal40
of preparing a metallopolymer by solid-/melt-state polymer-
ization (S(M)SP), we assume that S(M)SP would be a good
choice to prepare a conjugated Fc-containing polymer. Because
its only requirement is treating the monomers at an
appropriate temperature to promote the reaction, S(M)SP is
a solvent-free, catalyst-free, and easy to implement method to
prepare polymers. Since it was discovered in the early 1960s,41
S(M)P has been widely applied in the synthesis of conjugated
polythiophene derivatives.42−48
Received: May 11, 2019
© XXXX American Chemical Society
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Herein, two kinds of Fc-containing monomers, thiophene
based (FcT and FcT8) and thiophene methine based (FcTP
and FcTP8), have been synthesized and subsequently been
subjected to S(M)SP to acquire the polymers. The soluble Fc-
containing polymers PFcT8 and PFcTP8 were obtained
1
successfully and were characterized by H NMR, UV−vis,
and FTIR spectra, cyclic voltammetry, gel permeation
chromatography (GPC), and inductively coupled plasma
atomic emission spectrometry (ICP). Due to the high stability
of the Fc group and moderate reaction temperature, little
degradation occurred in the polymerization process and the
metallopolymers were obtained with regular backbones and
nearly quantitative metal contents.
2. RESULTS AND DISCUSSION
2.1. Structure and Polymerization Pathway. The
disubstituted ferrocene monomers (Scheme 1) were synthe-
Scheme 1. General Synthetic Routes to Disubstituted
Ferrocenes
Figure 1. (a) Crystal structures of FcT with thermal ellipsoids drawn
at the 30% level. All hydrogen atoms are omitted for clarity. (b) The
shortest and longest atom distances as well as the plane angle between
two thiophene rings. (c) The shortest intermolecular C−C and Br−Br
distances in the FcT crystal.
respectively, which are both within the π−π effect range.50
A
small plane angle between the two thiophene-determined
planes of 5.57° was also observed. The possible polymerization
pathway of FcT was proposed from the monomer’s crystal
structure. As shown in the crystal packing map (Figure 1c), the
shortest intermolecular Hal−Hal (Br1−Br2) distance is 4.412
Å and the shortest C1−C10 distance is 5.314 Å, which are
longer than those of our previously reported metal complexes40
(4.044 Å for Hal−Hal distance and 4.935 Å for C1−C10
distance). However, there is an infinite ···C1−C10−C1−
C10··· chain in FcT, which means FcT has an far shorter
effective Hal−Hal distance of 4.412 Å (6.602 and 6.827 Å in
the reported metal complexes), resulting in a lower onset
temperature. These results indicate that the possible polymer-
ization pathway of FcT is along the b axis and follows the ···
C1−C10−C1−C10··· sequence.
2.2. Characterization of Fc-Containing Polymers. As
shown in Scheme 2, the polymers were prepared through melt-
state polymerization (MSP) by heating their monomers in a
glass tube under a nitrogen atmosphere at a specific
temperature (Table 1). The final reaction conditions were
sized according to the reported method,49 where the
substituents (RX) were halogen-substituted thiophene deriv-
atives (TX and T8X) or thiophene-methine derivatives (TPX
and TP8X). The monomers FcT and FcTP were designed as
models to acquire the structure information on the complexes,
whereas the 2-ethylhexyl group was introduced onto FcT8 and
FcTP8 to improve the solubility of the corresponding
metallopolymers.
Scheme 2. Synthesis of Ferrocene-Containing Polymers
with MSP
Single crystals of FcT suitable for single-crystal X-ray
analysis were grown in a dichloromethane/diethyl ether
mixture. As shown in Figure 1, due to the strong π−π
interaction between the electron-rich thiophene rings, the FcT
adopts a cis configuration with two parallel thiophene rings.
The shortest and longest atom distances between two
thiophene rings are 3.505 and 3.792 Å (Figure 1b),
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Table 1. Preparation Details and Properties of Fc-
Containing Polymers
PFcT8
110
PFcTP8
a
Tonset
,
°C
80
reaction conditions
yield, %
Mn of polymer, KDa
DP
122 °C, 24 h
>90
7.8
110 °C, 48 h
ca. 65
11.6
13
10
dispersity (Đ)
calcd Fe content, %
tested Fe content, %
1.01
9.32
8.53
1.15
4.70
4.46
a
T
onset is determined by the color change of the mixture to dark after
heating for 2 h.
optimized by taking a comprehensive consideration of the
solubility, molecular weight, and yield of polymer. The reaction
rate of FcT8 is slow when the temperature is below 120 °C
and is fast and leads to an insoluble polymer when the
temperature is raised to 125 °C. The polymer PFcT8 obtained
by heating at 122 °C for 24 h has a high yield (>90%) but
shows poor solubility. For PFcTP8, a low reaction temperature
was needed to ensure a good solubility and avoid degradation,
while a long reaction time was applied to improve the yield.
After reaction at 110 °C for 48 h, unreacted monomer was first
removed by hexane and the final product was extracted by
Soxhlet extraction with dichloromethane as solvent. The
polymerization temperatures of both Fc-containing polymers
are lower than those of our previously reported thiophene-
methine based metallopolymers40 but higher than those other
metal-free polymers with a thiophene-methine structure.51
The preparation details and physical properties of metal-
lopolymers are given in Table 1. The molecular weights (Mn)
of PFcT8 and PFcTP8 are 7.8 and 11.6 kDa, respectively,
corresponding to polymerization degrees (DPs) of 13 and 10
(GPC traces are available in Figure S1). Moreover, the Fe
content was confirmed by ICP (Table 1), which shows that ca.
92% and 95% of Fe remain in PFcT8 and PFcTP8,
respectively. In our recent work toward preparing metal-
lopolymers with pendant coordination fragments by S(M)SP,
50−70% of the metal was expelled due to the high reaction
temperature.40 Fortunately, the remaining metal contents of
these Fc-containing polymers are higher than those of the
previously reported metallopolymers40 due to the high stability
of Fc and low polymerization temperature. In addition to the
stable coordination group (Fc), the thiophene-methane
structure bearing a small pendant group is also vital to access
high-metal-content metallopolymers by decreasing the reaction
temperature. These results indicate that it is possible to acquire
a defect-free metallopolymer of almost 100% metal content by
S(M)P when a carefully designed monomer is applied.
1
Figure 2. H NMR spectra of neutral polymers (a) PFcT8 and (b)
PFcTP8. The asterisk denotes the vacuum grease.
H (and phenyl-H) are close to their theoretical values of 1:2 in
PFcTP8 and 1:0.25 in PFcT8, which indicates that the
structures of the polymers are highly regular.
Their structures were also confirmed by the FTIR spectra.
As shown in Figure 3, the broad peaks at ca. 3430 cm−1 are
ascribed to the −OH groups of water from the air, whereas the
peaks at 2835−3000 cm−1 are ascribed to the stretching
vibration of C−H in the ferrocene, phenyl rings, and alkyl. The
out-of-plane CH bending vibrations from the Cp ring are
observed at 1170 and 1023 cm−1.53 The peaks at ca. 815, 1379,
and 1457 cm−1 are characteristic of the thiophene ring. In
The structure information on those polymers was first
studied by an 1H NMR analysis. As shown in Figure 2, the Fc-
H signals appear at 4.18 ppm for PFcT8 and 4.41 and 4.64
ppm for PFcTP8 (marked as 3), whereas the aromatic
thiophene proton signals are located at 6.82−7.09 ppm for
PFcTP8 and 6.73 ppm for PFcT8 (marked as 2). In
comparison with PFcT8, apart from the phenyl protons
appearing at 6.66 ppm (marked as 4), the PFcTP8 has another
new signal at 7.52 ppm (marked as 5), which is characteristic
of a quinoid thiophene.52 The absence of methenyl-H in
PFcTP8 (Figure 2b) means that the polymer has a regular
quinoid structure. In addition, the ratios of Fc-H to thiophene-
Figure 3. FTIR absorption spectra of the monomers and metal-
lopolymers.
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PFcTP8, in addition to the intense peak at 1601 cm−1 that is
ascribed to the phenyl group, another new absorption peak
around 1657 cm−1 is assigned to the quinoid structure of
thiophene.
The UV−vis spectra of monomers and polymers are shown
in Figure 4a. The absorption band at 420−550 nm originates
oxidation feature of the Fc moiety. PFcTP8 has versatile
oxidation behavior in comparison to PFcT8, such as oxidation
peaks at 0.31, 0.6, and 1.2 V, which are assigned to the
oxidation of the thiophene-methine structure. The property of
multistep irreversible oxidation of PFcTP8 is similar that of
our previously reported poly(thiophene methine) deriva-
tives.42,51
The thermal stabilities of the prepared polymers were
investigated by thermogravimetric analysis (TGA), which was
recorded in the range of room temperature to 580 °C under a
nitrogen atmosphere at a heating rate of 10 °C min−1. As
shown in Figure 6, PFcT8 is stable when the temperature is
Figure 4. UV−vis spectra of (a) ferrocene-containing monomers and
polymers in CH2Cl2 and (b) polymers before (PFcT8 and PFcTP8)
and after (PFcT8-R and PFcTP8-R) treatment with hydrazine
hydrate.
from characteristic d−d electronic transitions of the ferrocenyl
groups.54 Both of the monomers show an absorption peak
around 454 nm, whereas the polymers PFcT8 and PFcTP8,
which have extended conjugated backbones, show red-shifted
absorptions at around 468 and 502 nm, respectively. The
π−π* band gap transitions of the polymer are observed around
550−730 nm for PFcT8 and 730−1100 nm for PFcTP8,
which show a lower energy gap in comparison to other
reported thiophene-based40 or Fc-containing metallopoly-
mers.55−57 In addition, due to the existence of the
thiophene-methine structure, the polymer PFcTP8 has
another new absorption band at 550−730 nm and displays
broader spectra in comparison with PFcT8. After treatment
with hydrazine hydrate (85% in water/MeOH 1/20, v/v), both
of the reduction polymers (PFcT8-R and PFcTP8-R) show
lower absorption values but little peak shift in comparison to
their freshly made polymers (Figure 4b). When the ratio of
polymer to hydrazine hydrate was decreased, the absorption of
PFcTP8 decreased at first and ended at a stable value (Figure
S3), which is a result of the doping state of these freshly made
polymers and the dedoping effect of the hydrazine hydrate.
The electrochemical behaviors were analyzed by cyclic
voltammograms (CV); as shown in Figure 5, the redox peaks
of the Fc moiety in monomers FcT8 and FcTP8 and polymers
PFcT8 and PFcTP8 appear at 0.21, 0.01, 0.13, and 0.09 V,
respectively. These assignments were made according to the
reported literature58 and the reversible/quasi-reversible
Figure 6. Thermogravimetric analysis (TGA) of PFcT8 and PFcTP8
measured at a heating rate of 10 °C/min under a nitrogen
atmosphere.
lower than 254 °C, and a small platform at 254−325 °C that
results from further polymerization of polymer is observed.
With an increase in the temperature, the weight of PFcT8 is
decreased because of decomposition, and a weight loss of 45%
is observed when the temperature is up to 580 °C. The further
polymerization platform of PFcTP8 appears at 185−250 °C,
and a gradual weight loss of 10% is observed at 405 °C. In the
range of 405−505 °C, PFcTP8 undergoes a rapid decom-
position with 49% weight loss, which is similar to that of some
other reported Fc-containing polymers.1,59 In comparison with
PFcT8, PFcTP8 has a softer backbone and has more alkyl
chains, which can cause more serious intermolecular and
intramolecular interactions and thus result in a higher
decomposition temperature.
3. CONCLUSIONS
A facile method of MSP was successfully applied to the
synthesis of conjugated main-chain Fc-containing polymers
that integrated the Fc motif with thiophene or thiophene-
methane groups, where the thiophene or thiophene-methane
groups served as reactive sites for use in S(M)P. The prepared
metallopolymers have regular backbones and high metal
contents of more than 92%, which prove that bulk polymer-
ization is a good choice to prepare conjugated metallopolymers
when a carefully designed monomer is applied. Moreover,
these metallopolymers have small band gaps with an
absorption edge to 730 and 1100 nm for PFcT8 and
PFcTP8, respectively, which are very small among reported
Fc-containing polymers as far as we know. The low band gap
and high stability of PFcTP8 suggest that the thiophene-
methane based Fc-containing structure is an excellent
candidate to build functional Fc-containing polymers, which
have potential application in conducting materials with high
working temperature.
Figure 5. Cyclic voltammograms of ferrocene-containing monomers
(a) and polymers (b) in CH2Cl2. Conditions: 0.1 M TBAP, scan rate
50 mV/s.
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1
4.3.3. FcTP: brick red powder, yield 1.45 g, 34%; H NMR (400
MHz, CDCl3) δ 7.29−7.36 (m, 10H), 6.90 (d, J = 4 Hz, 2H), 6.62 (d,
J = 4 Hz, 2H), 6.57 (d, J = 4 Hz, 2H), 6.49 (d, J = 4 Hz, 2H), 5.62 (s,
2H, CH), 4.33 (d, J = 4 Hz, 4H), 4.17 (d, J = 4 Hz, 4H) ppm; 13C
NMR (101 MHz, CDCl3) δ 149.15, 143.70, 142.70, 141.40, 129.38,
128.64, 128.29, 127.39, 126.52, 126.28, 121.87, 111.24, 81.27, 70.37,
68.53, 68.51, 47.93 ppm; MS (ESI) m/z calculated for C40H28S4Br2Fe
851.88, found 852.88 (M + H+). Anal. Found for C40H28S4Br2Fe: C,
56.17; H, 3.26. Calcd: C, 56.35; H, 3.31.
4. EXPERIMENTAL SECTION
The experimental materials, characterization details, and partially
synthesis details are available in the Supporting Information.
4.1. Synthesis of TX/T8X. TX and T8X were prepared by a
reported method60 by iodization of their 2-bromothiopthene
derivatives. To a solution of 2-bromothiopthene derivative (20
mmol) in CH2Cl2 (50 mL) were added iodine (11.2 mmol) and
iodobenzene diacetate (12.2 mmol) at 0 °C. After the mixture was
stirred at room temperature for 5 h, 10% aqueous Na2S2O3 was
added, and the mixture was extracted with Et2O. The organic phase
was collected and dried over anhydrous Na2SO4. After filtration, the
organic solvents and iodobenzene were removed by evaporation
under reduced pressure. The oil was purified by silica gel column
chromatography using petroleum ether as the eluent and further
purified by vacuum distillation to give the product (yield 92% for TX
and 96% for T8X).
4.3.4. FcTP8: brick red oil, stored at −18 °C, yield 1.86 g, 28%; 1H
NMR (400 MHz, CDCl3) δ 7.09 (d, J = 8.4 Hz, 4H), 6.87 (d, J = 4
Hz, 2H), 6.58−6.63 (m, 8H), 6.51 (d, J = 4 Hz, 2H), 5.51 (s, 2H,
CH), 4.34 (d, J = 4 Hz, 4H), 4.15 (d, J = 4 Hz, 4H), 3.14−3.21 (m,
8H), 1.78 (m, 4H), 1.25−1.30 (m, 32H), 0.83−0.90 (m, 24H) ppm;
13C NMR (101 MHz, CDCl3) δ 150.69, 147.62, 145.16, 140.93,
129.30, 129.05, 128.83, 126.13, 125.86, 121.88, 112.42, 110.83, 81.54,
70.48, 68.42, 56.47, 47.18, 36.70, 30.70, 28.71, 28.69, 23.97, 23.27,
14.18, 10.74 ppm; MS (ESI) m/z calculated for C72H94N2S4Br2Fe
4.2. Synthesis of TPX/TP8X. TPX and TP8X were prepared by
our previously reported method.40 To a mixture of aldehyde (10
mmol) and 2-bromothiophene (40 mmol) dissolved in glacial acetic
acid (40 mL) was added a solution of BF3 (46.7 wt % in Et2O, 5 mL).
After the aldehyde reacted completely (monitored by TLC; a long
reaction time leads to polymerization of the product), the brown
solution was poured into 100 mL of cooled water and the product was
extracted with ethyl acetate. The organic phase was washed with
aqueous Na2CO3 and dried over anhydrous Na2SO4, and the solvent
was removed by rotary evaporator. The oil was purified by column
chromatography on silica gel.
1330.40, found 1331.41 (M
+
H+). Anal. Found for
C72H94N2S4Br2Fe: C, 64.61; H, 7.03; N, 2.06. Calcd: C, 64.95; H,
7.12; N, 2.10.
4.4. Synthesis of Metallopolymers. In the general procedure,
the metal complex monomer was sealed in a glass tube under a
nitrogen atmosphere, and then the glass tube was placed in a muffle
furnace and heated at a specific temperature (Table 1). The onset
polymerization temperature was determined by the color change of
the mixture from brick red to dark after heating for 2 h.
4.4.1. PFcT8. After the reaction was completed, the obtained solid
was ground to a powder, washed with hexane until the solvent
become clean and then washed with methanoland water, and dried
under vacuum. PFcT8 was obtained as a black solid.
4.4.2. PFcTP8. After the reaction was completed, the obtained oil
was washed with hexane until the solvent become clean and a black
solid remained. The precipitate was extracted by Soxhlet extraction
with dichloromethane as solvent, the organic phase was collected, and
PFcTP8 was obtained as a black solid after removing the solvent.
TPX data were in accord with those in the literature.61
4.2.1. TP8X: colorless oil, yield 7.95 g, 92%; H NMR (400 MHz,
1
CDCl3) δ 7.05 (d, J = 8 Hz, 2H), 6.86 (d, J = 8 Hz, 2H), 6.58 (d, J =
4 Hz, 4H), 5.52 (s, 1H, CH), 3.14−3.23 (m, 4H), 1.76−7.78 (m,
2H), 1.26−1.37 (m, 16H), 0.83−0.89 (m, 12H) ppm; 13C NMR (101
MHz, CDCl3) δ 149.66, 147.72, 129.36, 128.77, 128.21, 126.09,
112.38, 111.17, 56.46, 47.16, 36.65, 30.69, 28.70, 23.96, 23.28, 14.18,
10.73 ppm; MS (ESI) m/z calculated for C31H43NS2Br2 653.12, found
654.12 (M + H+). Anal. Found for C31H43S2Br2N: C, 56.79; H, 6.49;
N, 2.07. Calcd: C, 56.97; H, 6.63; N, 2.14.
4.3. General Procedure for Syntheses of Disubstituted
Ferrocenes. All of the reactions were carried out under Ar2. In a dry
flask containing ferrocene (0.93 g, 5 mmol), dry hexane (10 mL), and
tetramethylethylenediamine (TMEDA, 1.34 g, 11.5 mmol) was placed
n-BuLi (2.5 M, 4.4 mL, 11 mmol) at 30 °C. After the mixture was
stirred at room temperature for 24 h, 1,1′-dilithioferrocene formed as
a pale orange precipitate. The solvent was removed, and the
precipitate was washed with hexane (3 × 8 mL) and dried under
reduced pressure. The obtained pale orange powder was dissolved in
THF (10 mL) and cooled to −10 °C, and ZnCl2 (1 M in THF, 11
mL, 11 mmol) was added. After the mixture was stirred at −10 °C for
20 min and then at 30 °C for another 1 h, Pd(PPh3)4 (0.29 g, 0.25
mmol) and RX (15 mmol) were added. After it was stirred at room
temperature for 2 days, the mixture was poured into 200 mL of brine
and extracted with EA. The organic phase was collected and dried
over anhydrous Na2SO4, and the solvent was removed under reduced
pressure. The residue was purified by silica gel column chromatog-
raphy using petroleum ether as eluent.
ASSOCIATED CONTENT
■
S
* Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.organo-
met.9b00312.
Additional experimental details and supporting figures
(PDF)
Accession Codes
CCDC 1903413 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
via www.ccdc.cam.ac.uk/data_request/cif, or by emailing
data_request@ccdc.cam.ac.uk, or by contacting The Cam-
bridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
1
4.3.1. FcT: brick red powder, yield 1.09 g, 43%; H NMR (400
AUTHOR INFORMATION
■
MHz, CDCl3) δ 6.78 (d, J = 4 Hz, 2H), 6.59 (d, J = 4 Hz, 2H), 4.41
(d, J = 4 Hz, 4H), 4.23 (d, J = 4 Hz, 4H) ppm; 13C NMR (101 MHz,
CDCl3) δ 142.93, 130.13, 122.72, 109.02, 80.98, 70.48, 68.05 ppm (in
accord with the literature50).
Corresponding Authors
*E-mail for J.Z.: jzhang03@whu.edu.cn.
*E-mail for J.X.: jbxia@whu.edu.cn.
1
4.3.2. FcT8: brick red oil, yield 1.79 g, 49%; H NMR (400 MHz,
ORCID
CDCl3) δ 6.45 (s, 2H), 4.46 (s, 4H), 4.29 (s, 4H), 2.41 (d, J = 4 Hz,
4H), 1.57−1.60 (m, 2H), 1.21−1.34 (m, 16H), 0.86−0.91 (m, 12H)
ppm; 13C NMR (101 MHz, CDCl3) δ 141.16, 140.48, 124.46, 107.19,
77.22, 70.92, 68.05, 39.86, 33.78, 32.47, 28.79, 25.66, 23.09, 14.18,
10.86 ppm; MS (ESI) m/z calculated for C34H44S2Br2Fe 732.06,
found 733.06 (M + H+). Anal. Found for C34H44S2Br2Fe: C, 55.49; H,
5.98. Calcd: C, 55.75; H, 6.05.
Qi Luo: 0000-0001-6393-0115
Jing Zhang: 0000-0003-4754-1659
Jiangbin Xia: 0000-0001-6238-4992
Notes
The authors declare no competing financial interest.
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(16) Hailes, R. L. N.; Oliver, A. M.; Gwyther, J.; Whittell, G. R.;
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ACKNOWLEDGMENTS
■
We thank the Natural Science Foundation of China
(21875173) and the Fundamental Research Funds for the
Central Universities (2042018kf0238, 2042019gf0028) of
China for support. We thank Yu Peng-Yuan for help with
the single-crystal X-ray diffraction measurements.
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Responsive Ferrocene-Containing Polymer Brushes. Eur. Polym. J.
2016, 83, 517−528.
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DOI: 10.1021/acs.organomet.9b00312
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