Synthesis of supramolecular precision polymers: Crystallization under conformational constraints

Article abstract of DOI:10.1002/pola.28759

Placing artificial folding elements into precision polymers is an important strategy to systematically study structure formation in self-assembly, particularly in the semicrystalline state. To this purpose, a series of precision polymers bearing either a N-protected or N-unprotected diaminopyridine (DAP) unit after every 16th, 18th, and 20th carbon as well as a urea unit after every 20th carbon along a polyethylene-like polymer were synthesized via acyclic diene metathesis polymerization and subsequent hydrogenation. The polymers thus contain either H-bonds (urea/DAP), π–π-elements (DAP), or no H-bonds (respective N?protected urea/DAP-units) in their main chain, able to consequently study the crystallization behavior under influence of such supramolecular moieties. Therefore, the thermal properties and crystallization behavior were analyzed via differential scanning calorimetry (DSC) as well as wide angle X-ray diffraction. The obtained crystalline polymer is influenced by the different supramolecular interactions existing between adjacent polymer chains and the varying defect size exerted by the incorporated functional groups.

Full text of DOI:10.1002/pola.28759

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Synthesis of Supramolecular Precision Polymers: Crystallization Under
Conformational Constraints
1
Sophie Reimann ,1 Varun Danke ,2 Mario Beiner ,2 Wolfgang H. Binder
1Institute of Chemistry, Macromolecular Chemistry, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
2
€
Fraunhofer Institut fur Mikrostruktur von Werkstoffen und Systemen IMWS, 06120 Halle (Saale), Germany
Correspondence to: W. H. Binder (E-mail: wolfgang.binder@chemie.uni-halle.de)
Received 5 July 2017; accepted 9 August 2017; published online 00 Month 2017
DOI: 10.1002/pola.28759
ABSTRACT: Placing artificial folding elements into precision pol-
ymers is an important strategy to systematically study struc-
ture formation in self-assembly, particularly in the
semicrystalline state. To this purpose, a series of precision pol-
ymers bearing either a N-protected or N-unprotected diamino-
pyridine (DAP) unit after every 16th, 18th, and 20th carbon as
moieties. Therefore, the thermal properties and crystallization
behavior were analyzed via differential scanning calorimetry
(DSC) as well as wide angle X-ray diffraction. The obtained
crystalline polymer is influenced by the different supramolecu-
lar interactions existing between adjacent polymer chains and
the varying defect size exerted by the incorporated functional
C
V
groups.
2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A:
well as
a urea unit after every 20th carbon along a
Polym. Chem. 2017, 00, 000–000
polyethylene-like polymer were synthesized via acyclic diene
metathesis polymerization and subsequent hydrogenation. The
polymers thus contain either H-bonds (urea/DAP), p–p-
elements (DAP), or no H-bonds (respective NAprotected urea/
DAP-units) in their main chain, able to consequently study the
crystallization behavior under influence of such supramolecular
KEYWORDS: acyclic diene metathesis; crystallization; differential
scanning calorimetry (DSC); polymer synthesis; precision poly-
mers; supramolecular polymer chemistry; WAXS
each other via ionic-forces or p–p-stacking as observed for
polymers bearing triazol-rings,29 sulfonic,30 or amino acid
groups in the main chain.31,32 Investigation of these inclu-
sion- or separation effects has been accomplished using
long chain alkanes and their derivatives33 as well as vari-
ous periodic copolymers34–38 differing in branch identity
and frequency. Thus, in chains reminiscent of polyethylenes
large defects such as higher alkyl substituents18,39 (starting
from propyl-branches) as well as phosphoesters12,40 or
polyhedral silsesquioxanes41 are excluded from the crystal
lattice into the interstitial space, especially if the alkyl chain
length between the defects is increased.39 If the excluded
branch exceeds the size of 10 carbons the defects can coc-
rystallize,39,42 also observed for polymers bearing perfluori-
nated chains,28 where the segregation was facilitated by the
immiscibility between the polymer backbone and the
branch, leading to additional ordering effects on the crystal-
lization. In contrast, small defects such as methyl39,43-,
ethyl44-, or halogen11,13,45–47-branches can be incorporated
into the crystalline region of the polyethylene (PE) -chains,
whereby the orthorhombic structure is preserved up to a
defect size of about 1.6 Å.45
INTRODUCTION The crystallization of polymers in nano-
scopic domains can strongly be influenced by constraints,
either exerted from the “outside” (e.g., geometrical confine-
ment by alumina nanopores1–4) or “self-assembled con-
straints” occurring in two-phasic polymers, where the
crystallization of one phase is strongly influenced by the sec-
ond phase in the environment. Famous examples for the lat-
ter case are block copolymers, where glassy or crystalline
matrices influence the crystallization of crystallizable
domains with typical domain sizes of about 10–50 nm,5–7 or
nanophase separated polymers with comb-like architecture,
where constraints introduced by ring-type subunits located
in a crystalline nanolayer can disturb the crystallization
behavior of long methylene sequences.8–10 In case of linear
polymers, where long methylene sequences alternate with
functional groups (“defects”) within the polymer backbone,
their incorporation or exclusion into crystalline regions has
been intensively studied.11–26 Especially precision polymers,
resulting from acyclic diene metathesis (ADMET) polymeriza-
tion27 or “click”-based oligomerization chemistries,28,29 have
been investigated in this context, often observing a layered
arrangement of defects if the included moieties interact with
Additional Supporting Information may be found in the online version of this article.
C
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SCHEME 1 Synthetic route for (a) the preparation of unprotected and protected DAP monomers (1a–c, 2a–f), (b) the preparation of
the urea monomer (5), and (c) the ADMET polymerization and subsequent hydrogenation.
The idea of this work is to design and investigate polymers,
where folding-constraints are introduced repetitively into long
methylene sequences (n 5 16, 18, and 20), frustrating their
folding such that the packing behavior of the methylene
sequences48,49 can exhibit a lamellar morphology. A recent
study has shown that the methylene sequences in such poly-
mers may be ordered or disordered depending on the thermal
history as well as the length of the alkyl groups, also observing
polymorphic states for the same side chain lengths.8
All chemicals were purchased from Sigma-Aldrich and used
without further purification if not mentioned otherwise. All
solvents were either distilled and/or dried using standard
methods.
Tetrahydrofuran (THF) was predried over KOH and freshly
distilled from sodium/benzophenone under an atmosphere
of dry nitrogen. Dichloromethane (DCM) was predried over
CaCl2 and freshly distilled from CaH2 before use. Before
using sodium hydride (60% in mineral oil), it was washed
several times with dry THF and stored under an atmosphere
of nitrogen.
We here report on the synthesis of precision polymers bear-
ing defects, which are repetitively located within a PE-chain
and feature hydrogen-bonding and aromaticity as shown in
Scheme 1. Thus, N-substituted 2,6-diaminopyridine-moieties
(DAP) have been chosen to study the effect of H-bonds onto
the crystallization behavior of the alkyl units, protecting the
amides via either methyl- or benzyl units to probe the effect
of bulkiness of the non-hydrogen moieties on the structure
formation, whereas the absence of the protecting group
should enable strong intermolecular hydrogen bonds, now
acting between the chains in the crystal. Furthermore, the
aromatic DAP element was replaced by a simple urea moiety,
devoid of p–p-stacking interactions. The synthetic prepara-
tion of the polymers and the influence of the main chain
defects on the molecular ordering in the solid state are
reported in detail.
NMR spectra were recorded in CDCl3 (Chemotrade, 99.8%
Atom%D) on a Varian spectrometer (Gemini 400) at 400
MHz or on a Varian Unity Inova 500 (500 MHz) at 27 8C and
tetramethylsilane as internal standard. The coupling con-
stants were given in Hz and the chemical shifts in ppm and
referred to the solvent residue peak [CDCl3 7.26 ppm (1H)
and 77.0 ppm (13C)]. MestReNova v. 8.0.0–10524 was used
for the interpretation of the spectra.
Size exclusion chromatography (SEC) measurements were per-
formed on a Viscotek GPCmax VE2001, equipped with a
GMHHR-N-18055 and a SMT-3000 column in THF at 25–30 8C
with a sample concentration of 1 mg mL21. The injection vol-
ume was 100 mL and the detection was carried out via a refrac-
tive index detection using a VE3580 RI detector or via UV
detector (model no. 2600) of Viscotek at a temperature of
35 8C and a flow rate of 1 mL min21. For external calibration,
polystyrene standards with molecular weights of 1050, 2790,
6040, 13,400, and 29600 g mol21 were used.
EXPERIMENTAL
Dodec-11-enoic acid, dec-9-enoyl chloride, undec-10-enoyl
chloride, and dodec-11-enoyl chloride were synthesized
according to literatures.37,50
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Electrospray ionization-time-of-flight (ESI-ToF) mass spec-
trometry (MS) measurements were performed on a Focus
microToF by Bruker Daltonics. The sample (1.00 mg) was
dissolved in methanol (1.00 mL, HPLC grade, received from
Sigma-Aldrich) and directly injected (180 mL h21, positive or
negative mode). The interpretation of the data was carried
out using DataAnalysis Version 4.0 from Bruker.
X-ray optic (ASTIX) as monochromator for Cu Ka radiation
(k 5 0.154 nm). A DECTRIS PILATUS3 R 300K detector was
used to record the two-dimensional scattering patterns. As
sample holders 2 mm thick aluminum discs with a central
hole were used. The measurements were performed at room
temperature in vacuum for three samples to detect distances
to cover a wider q-range (q 5 0.05–3 nm21; 0.25–7 nm21
,
and q 5 1–29 nm21). Before the measurement the samples
were annealed for 24 h at 40 8C followed by cooling them to
room temperature.
Matrix-assisted laser desorption ionization (MALDI)-ToF MS
measurements were performed on a Bruker Autoflex III Sys-
tem (Bruker Daltonics) operating in the linear and reflection
mode. Ions were formed by laser desorption (smart beam
laser at 355, 532, 808, and 1064 6 5 nm; 3 ns pulse width;
up to 2500 Hz repetition rate), accelerated by a voltage of
19–20 kV and detected as positive ions. The matrix trans-2-
[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononi-
trile (purchased from Sigma-Aldrich), the salt lithiumtrifluor-
oaetate (purchased from Sigma-Aldrich) as well as the
polymer sample were dissolved in THF with a concentration
of 20 mg mL21 each. The solutions of the matrix, the poly-
mer, and the salt were mixed in a volume ratio of 25:5:1 and
1 mL of each mixture was spotted on the MALDI target. Cali-
bration was carried out with poly(ethylene glycol) mono-
methyl ether (PEG) (Mn 5 4200 g mol21, Mw/Mn 5 1.05) as
external standard. The interpretation of the data was carried
out using flexAnalysis Version 3.4 (build 76) from Bruker.
Fourier-transform infrared spectroscopy (FTIR) was per-
formed as KBr pellet on a Bruker Vertex 70 MIR using Opus
6.5 for data interpretation.
For thin-layer chromatography (TLC) Merck TLC aluminum
sheets (silica gel 60 F254) were used. The resulting spots
were visualized by UV light (254 nm) or by the oxidizing
agent “blue stain.” This was prepared by dissolving
Ce(SO4)2ꢀ4H2O and (NH4)6Mo7O24ꢀ4H2O in a mixture of dis-
tilled water and concentrated sulfuric acid.
Column chromatography was performed with Kieselgel 60
(230–400 mesh), which was received from Merck.
Monomer Synthesis
General Synthesis of the ADMET Monomers Containing the
DAP Group
Differential scanning calorimetry (DSC) measurements were
performed on a NETZSCH DSC 204F1 Phoenix, which was
calibrated with indium, tin, and zinc. The samples (3–8 mg)
were filled in standard aluminum pans with a pierced lid,
heated above their melting point, and cooled to room tem-
perature to erase the previous thermal history. Afterwards
the samples were subjected to a thermal program using a
heating rate of 10 K/min. Interpretation of the obtained data
was performed with Netzsch Proteus—Thermal Analysis
(version 5.2.1) and OriginPro 2016G. The crystallinity Xc was
calculated according to the equation given below
All DAP monomers were synthesized in a biphasic Schotten–
Baumann reaction according to our previous investigations.51
A one-necked flask was filled with 2,6-diaminopyridine (1
eq.) and NaOH (2 eq.), which were dissolved in water. The
mixture was cooled in an ice-water bath and dec-9-enoyl
chloride, undec-10-enoyl chloride, or dodec-11-enoyl chloride
(2.3 eq.) dissolved in DCM was added slowly for 15 min.
After the mixture was allowed to stir for 2 h the organic
layer was separated and dried over Na2SO4. The solvent was
removed in vacuum at 45 8C and the crude product was
purified via column chromatography (silica gel 60, hexane/
ethyl acetate (EA) 8:2) to yield a white solid (92–94%).
DHm
Xc5
3100
(1)
DHm0
1
DAP-M-7 (1a): H NMR (400 MHz, CDCl3, d): 7.89 (d, J 5 8.0
Hz, 2H, CH) 7.68 (t, J 5 8.1 Hz, 1H, CH), 7.57 (s, 2H, NH),
5.93–5.65 (m, 2H, @CH), 5.08–4.82 (m, 4H, @CH2), 2.36 (t,
J 5 7.5 Hz, 4H, CH2), 2.12–1.97 (m, 4H, CH2), 1.82–1.60 (m,
4H, CH2), 1.49–1.14 (m, 16H, CH2). 13C NMR (101 MHz,
CDCl3, d): 171.6 (C@O), 149.5 (C3), 141.0 (C1), 139.2 (C12),
114.4 (C13), 109.5 (C2), 38.0 (C5), 33.9 (C11), 29.3 (C7),
29.3 (C8), 29.0 (C10), 29.0 (C9), 25.5 (C6). HRMS (ESI, m/z):
[M 1 Na]1 calcd for C25H39N3O2, 436.2934; found, 436.3250.
where DHm0 is the fusion enthalpy of the corresponding
alkane (hexadecane DHm0 5 225.146
J
g21
,
octadecane
DHm0 5 232.269 J g21 or eicosane DHm0 5 247.3 J g21) with
100% crystallinity.
Initial X-ray diffraction screening experiments for the satu-
rated DAP-polymers with methyl protection groups (n 5 16,
18, 20) were performed on a glass plate by cooling the sam-
ple from the isotropic liquid on a temperature-controlled
heating stage. The two-dimensional patterns were recorded
by an area detector VÅNTEC500 (Bruker AXS) using Ni-
filtered CuKa radiation at a sample-detector distance of
8.95 cm and an exposure time of 30 min.
1
DAP-M-8 (1b): H NMR (400 MHz, CDCl3, d): 7.89 (d, J 5 8.1
Hz, 2H, CH), 7.69 (t, J 5 8.1 Hz, 1H, CH), 7.56 (s, 2H, NH),
5.96–5.66 (m, 2H, @CH), 5.09–4.84 (m, 4H, @CH2), 2.36 (t,
J 5 7.5 Hz, 4H, CH2), 2.03 (dd, J 5 6.8 Hz, 4H, CH2), 1.82–1.59
(m, 4H, CH2), 1.47–1.15 (m, 20H, CH2). 13C NMR (101 MHz,
CDCl3, d): 171.6 (C@O), 149.6 (C3), 141.0 (C1), 139.3 (C13),
114.3 (C14), 109.5 (C2), 38.0 (C5), 33.9 (C12), 29.4 (C8),
29.4 (C10), 29.3 (C9), 29.2 (C11), 29.0 (C7), 25.5 (C6).
X-ray scattering experiments were performed in transmission
mode using a SAXSLAB laboratory setup (Retro-F) equipped
with an AXO microfocus X-ray source with an AXO multilayer
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HRMS (ESI, m/z): [M 1 Na]1 calcd for C27H43N3O2,
464.3247; found, 464.3571.
(C13), 29.8 (C8), 29.5 (C7), 29.5 (C10), 29.5 (C11), 29.2
(C9), 29.1 (C12), 25.5 (C6). HRMS (ESI, m/z): [M 1 Na]1
calcd for C31H51N3O2, 520.4893; found, 520.5265.
DAP-M-9 (1c): 1H NMR (400 MHz, CDCl3, d): 7.90 (d, J 5 8.1
Hz, 2H, CH), 7.69 (t, J 5 8.1 Hz, 1H, CH), 7.52 (s, 2H, NH),
5.90–5.72 (m, 2H, @CH), 5.05–4.87 (m, 4H, @CH2), 2.36 (t,
J 5 7.5 Hz, 4H, CH2), 2.12–1.97 (m, 4H, CH2), 1.76–1.67 (m,
4H, CH2), 1.45–1.21 (m, 24H, CH2). 13C NMR (101 MHz,
CDCl3, d): 171.6 (C@O), 149.6 (C3), 141.0 (C1), 139.3 (C14),
114.3 (C15), 109.5 (C2), 38.0 (C5), 33.9 (C13), 29.6 (C8),
29.5 (C10), 29.5 (C11), 29.3 (C7), 29.2 (C9), 29.1 (C12), 25.5
(C6). HRMS (ESI, m/z): [M 1 Na]1 calcd for C29H47N3O2,
492.3560; found, 492.3496.
DAP-M-Bn-7 (2d): 1H NMR (400 MHz, CDCl3, d): 7.61 (t,
J 5 7.9 Hz, 1H, CH), 7.26–7.14 (m, 10H, CH), 7.10 (d, J 5 7.6
Hz, 2H, CH), 5.92–5.69 (m, 2H, @CH), 5.22–4.79 (m, 8H,
@CH2), 2.24 (t, J 5 7.3 Hz, 4H, CH2), 2.06–1.91 (m, 4H, CH2),
1.67–1.53 (m, 4H, CH2), 1.38–1.13 (m, 16H, CH2). 13C NMR
(101 MHz, CDCl3, d): 173.6 (C@O), 154.1 (C3), 139.7 (C12),
139.2 (C1), 137.6 (C15), 128.6 (C17), 127.7 (C16), 127.3
(C18), 119.0 (C13), 114.3 (C2), 51.0 (C14), 35.3 (C5), 33.9
(C11), 29.4 (C7), 29.4 (C8), 29.1 (C10), 29.0 (C9), 25.4 (C6).
HRMS (ESI, m/z): [M 1 H]1 calcd for C39H51N3O2, 594.4054;
found, 594.4369.
General Procedure for the Protection of the DAP
Monomers
DAP-M-Bn-8 (2e): 1H NMR (400 MHz, CDCl3, d): 7.61 (t,
J 5 7.9 Hz, 1H, CH), 7.25–7.17 (m, 6H, CH), 7.15–7.04 (m, 6H,
CH), 5.86–5.74 (m, 2H, @CH), 5.04–4.98 (m, 4H, CH2), 4.97–
4.89 (m, 4H, @CH2), 2.24 (t, J 5 7.4 Hz, 4H, CH2), 2.02 (dd,
J 5 14.4 Hz, J 5 6.9 Hz, 4H, CH2), 1.63–1.56 (m, 4H, CH2),
1.38–1.15 (m, 20H, CH2). 13C NMR (101 MHz, CDCl3, d):
173.6 (C@O), 154.1 (C3), 139.7 (C13), 139.3 (C1), 137.6
(C16), 128.6 (C18), 127.7 (C19), 127.3 (C17), 119.0 (C2),
114.3 (C14), 51.0 (C15), 35.3 (C12), 33.9 (C5), 29.5 (C7),
29.4 (C8), 29.4 (C10), 29.2 (C9), 29.0 (C11), 25.5 (C6).
HRMS (ESI, m/z): [M 1 Na]1 calcd for C41H55N3O2,
644.4186; found, 644.4227.
The protection of the amides (1a–c) with methyl and benzyl
protection groups was carried out as reported previ-
ously.51,52 A two-necked flask was filled with a solution of
the unprotected monomer 1a–c (1 eq.) and methyl iodide or
benzyl bromide (2.4 eq.) in dry THF and NaH (2.4 eq.) was
added portion wise at 0 8C. The reaction mixture was
allowed to warm up to room temperature and was stirred
overnight, followed by pouring carefully into ice water. After
extraction with ethyl acetate, the combined organic layers
were washed with water and dried over MgSO4. The solvent
was removed in vacuum at 45 8C and the crude product was
purified via column chromatography (silica gel 60, hexane/
EA 8:2) to yield pale yellow viscous oils (69–82%).
DAP-M-Bn-9 (2f): 1H NMR (400 MHz, CDCl3, d): 7.61 (t,
J 5 7.9 Hz, 1H, CH), 7.25–7.15 (m, 10H, CH), 7.10 (dd, J 5 7.7
Hz, J 5 1.9 Hz, 2H, CH), 5.95–5.66 (m, 2H, @CH), 5.05–4.83
(m, 8H, @CH2), 2.24 (t, J 5 7.5 Hz, 4H, CH2), 2.11–1.92 (m,
4H, CH2), 1.69–1.50 (m, 4H, CH2), 1.45–1.12 (m, 24H, CH2).
13C NMR (101 MHz, CDCl3, d): 173.6 (C@O), 154.1 (C3),
139.7 (C14), 139.3 (C1), 137.7 (C17), 128.6 (C19), 127.7
(C18), 127.3 (C20), 119.0 (C15), 114.3 (C2), 51.0 (C16), 35.3
(C5), 33.9 (C13), 29.6 (C9), 29.6 (C10), 29.5 (C8), 29.4 (C7),
29.3 (C12), 29.1 (C12), 25.5 (C6). HRMS (ESI, m/z):
[M 1 H]1 calcd for C43H59N3O2, 650.4680; found, 650.5027;
[M 1 Na]1 calcd for C43H59N3O2, 672.4499; found, 672.4245.
DAP-M-Me-7 (2a): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 7.9 Hz, 1H, CH), 7.24 (d, J 5 8.4 Hz, 2H, CH), 5.90–5.68
(m, 2H, @CH), 5.05–4.86 (m, 4H, @CH2), 3.36 (s, 6H, CH3),
2.36 (t, J 5 7.6 Hz, 4H, CH2), 2.01 (q, J 5 6.9 Hz, 4H, CH2),
1.74–1.55 (m, 4H, CH2), 1.44–1.15 (m, 16H, CH2). 13C NMR
(101 MHz, CDCl3, d): 173.7 (C@O), 155.0 (C3), 139.8 (C1),
139.2 (C12), 117.7 (C2), 114.3 (C13), 35.4 (C14), 35.3 (C5),
33.9 (C11), 29.4 (C7), 29.4 (C8), 29.1 (C10), 29.0 (C9), 25.4
(C6). HRMS (ESI, m/z): [M 1 Na]1 calcd for C27H43N3O2,
464.3247; found, 464.3555.
DAP-M-Me-8 (2b): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 8.2 Hz, 1H, CH), 7.24 (d, J 5 8.0 Hz, 2H, CH), 5.93–5.68
(m, 2H, @CH), 5.04–4.86 (m, 4H, @CH2), 3.36 (s, 6H, CH3),
2.36 (t, J 5 7.5 Hz, 4H, CH2), 2.12 (dd, J 5 7.3 Hz, J 5 1.6 Hz,
4H, CH2), 1.72–1.55 (m, 4H, CH2), 1.43–1.17 (m, 20H, CH2).
13C NMR (101 MHz, CDCl3, d): 173.7 (C@O), 155.0 (C3),
139.8 (C1), 139.3 (C13), 117.6 (C2), 114.3 (C14), 35.4 (C15),
35.3 (C12), 33.9 (C5), 29.5 (C7), 29.5 (C8), 29.5 (C10), 29.2
(C9), 29.0 (C11), 25.5 (C6). HRMS (ESI, m/z): [M 1 Na]1
calcd for C29H47N3O2, 492.3560; found, 492.3796.
Synthesis of Undec-10-enamide
The synthesis was carried out analogous to literature.50
A
two-necked flask was filled with a NH4OH solution (250 mL,
25% in H2O) and cooled to 0 8C. After dropwise addition of
undec-10-enoyl chloride (47.70 mmol, 9.0 g), dissolved in
THF (30 mL), the mixture was allowed to stir overnight. The
final product was separated by filtration and dried in vac-
uum to yield 8.17 g (44.57 mmol, 93%) of a white solid. (3)
1H NMR (400 MHz, CDCl3, d): 5.89–5.72 (m, 1H, @CH), 5.54
(d, 2H, NH2), 5.07–4.85 (m, 2H, @CH2), 2.25–2.17 (m, 2H,
CH2), 2.10–1.98 (m, 2H, CH2), 1.71–1.55 (m, 2H, CH2), 1.45–
1.17 (m, 10H, CH2). 13C NMR (101 MHz, CDCl3, d): 175.9
(C@O), 139.3 (C10), 114.3 (C11), 36.1 (C2), 33.9 (C9), 29.4
(C5), 29.4 (C6), 29.4 (C7), 29.2 (C4), 29.0 (C8), 25.7 (C3).
HRMS (ESI, m/z): [M 1 Na]1 calcd for C11H21NO, 206.1515;
found, 206.1449.
DAP-M-Me-9 (2c): 1H NMR (400 MHz, CDCl3, d): 7.74 (t,
J 5 7.9 Hz, 1H, CH), 7.24 (d, J 5 8.2 Hz, 2H, CH), 5.99–5.61
(m, 2H, @CH), 5.10–4.81 (m, 4H, @CH2), 3.36 (s, 6H, CH3),
2.36 (t, J 5 7.5 Hz, 4H, CH2), 2.13–1.93 (m, 4H, CH2), 1.64 (t,
J 5 7.4 Hz, 4H, CH2), 1.44–1.13 (m, 24H, CH2). 13C NMR (101
MHz, CDCl3, d): 173.7 (C@O), 155.0 (C3), 139.8 (C1), 139.3
(C14), 117.6 (C2), 114.2 (C15), 35.4 (C16), 35.3 (C5), 33.9
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Synthesis of Undec-10-en-1-amine
not be analyzed by the means of NMR spectroscopy or
MALDI-ToF MS due to their insolubility in any tested solvent.
The synthesis was carried out according to the literature.50
A two-necked flask was filled with undec-10-enamide (5.91
mmol, 1 g) dissolved in dry THF (30 mL). After cooling to
210 8C and careful addition of LiAlH4 (8.86 mmol, 0.34 g),
the mixture was allowed to stir overnight, followed by the
addition of dry Et2O (20 mL). By adding H2O (1 mL) and
then NaOH (2 mL, 10% in H2O) the reaction was quenched.
Afterwards, the mixture was filtered and dried over Na2SO4.
The solvent was removed in vacuum at 45 8C and the final
product was obtained as a white waxy solid (5.06 mmol,
86%). (4) 1H NMR (400 MHz, CDCl3, d): 5.89–5.71 (m, 1H,
@CH), 5.04–4.86 (m, 2H, @CH2), 2.67 (t, J 5 7.0 Hz, 2H, CH2),
2.10–1.96 (m, 2H, CH2), 1.48–1.22 (m, 14H, CH2). 13C NMR
(101 MHz, CDCl3, d): 139.4 (C10), 114.2 (C11), 42.4 (C1),
34.0 (C9), 33.9 (C2), 29.7 (C4), 29.6 (C5), 29.6 (C6), 29.3
(C7), 29.1 (C8), 27.0 (C3). HRMS (ESI, m/z): [M 1 H]1 calcd
for C11H23N, 170.1903; found, 170.1907.
DAP-uP-Me-16 (6d): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 7.9 Hz, 1H, CH), 7.23 (bs, 2H, CH), 5.88–5.69 (m, 2H,
@CH), 5.43–5.26 (m, 2H, @CH), 5.04–4.86 (m, 4H, @CH2),
3.36 (s, 6H, CH3), 2.36 (t, J 5 7.5 Hz, 4H, CH2), 2.05–1.87 (m,
8H, CH2), 1.75–1.52 (m, 4H, CH2), 1.38–1.13 (m, 28H, CH2).
13C NMR (126 MHz, CDCl3, d): 173.7 (C@O), 154.9 (C3),
139.8 (C1), 130.4 (C12), 117.6 (C2), 35.4 (C13), 35.3 (C5),
32.7 (C11), 29.9 (C7), 29.8 (C10), 29.5 (C8), 29.5 (C14), 29.3
(C9), 29.2 (C16), 27.3 (C15), 25.5 (C6).
DAP-uP-Me-18 (6e): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 7.9 Hz, 1H, CH), 7.26 (bs, 2H, CH), 5.91–5.71 (m, 2H, @CH),
5.45–5.20 (m, 2H, @CH), 5.07–4.73 (m, 4H, @CH2), 3.36 (s, 6H,
CH3), 2.36 (t, J 5 7.5 Hz, 4H, CH2), 2.07–1.85 (m, 4H, CH2),
1.73–1.52 (m, 8H, CH2), 1.24 (bs, 28H, CH2). 13C NMR (101
MHz, CDCl3, d): 173.7 (C@O), 154.9 (C3), 139.8 (C1), 139.3
(C18), 130.4 (C13), 117.7 (C2), 114.3 (C19), 35.4 (C14), 35.3
(C5), 33.9 (C17), 32.7 (C12), 29.9 (C8), 29.8 (C7), 29.6 (C11),
29.5 (C15), 29.5 (C16), 29.3 (C10), 29.2 (C9), 25.5 (C6).
Synthesis of 1,3-Diundec-10-en-1-ylurea
The synthesis was carried out according to the literature.53
A one-necked flask was filled with undec-10-en-1-amine
(4.99 mmol, 0.78 mg), ethylene carbonate (2.50 mmol,
0.22 mg), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) (0.05
mmol, 6.95 mg) and heated up to 130 8C for 2 h. After cool-
ing the mixture to room temperature the crude product was
purified via column chromatography (silica gel 60, DCM/EA
85:15) to yield 0.73 g of a pale yellow solid (1.99 mmol,
40%).
DAP-uP-Me-20 (6f): 1H NMR (500 MHz, CDCl3, d): 7.75 (t,
J 5 7.9 Hz, 1H, CH), 7.24 (d, J 5 3.9 Hz, 2H, CH), 5.88–5.64
(m, 2H, @CH), 5.47–5.12 (m, 2H, @CH), 5.07 – 4.78 (m, 4H,
@CH2), 3.36 (s, 6H, CH3), 2.36 (t, J 5 7.5 Hz, 4H, CH2), 2.08–
1.84 (m, 8H, CH2), 1.71–1.48 (m, 4H, CH2), 1.40–1.04 (m,
32H, CH2). 13C NMR (126 MHz, CDCl3, d): 173.7 (C@O),
155.0 (C3), 139.8 (C1), 139.3 (C19), 130.5 (C14), 117.7 (C2),
114.3 (C20), 35.4 (C15), 35.3 (C5), 33.9 (C18), 32.8 (C13),
29.9 (C10), 29.8 (C8), 29.6 (C7), 29.6 (C12), 29.6 (C16), 29.5
(C11), 29.5 (C9), 29.3 (C17), 25.5 (C6).
Urea-M-9 (5): 1H NMR (400 MHz, CDCl3, d): 5.88–5.74 (m,
2H, @CH) 5.06–4.88 (m, 4H, @CH2), 4.23 (s, 2H, NH), 3.14 (t,
J 5 7.1 Hz, 4H, CH2), 2.12–1.96 (m, 4H, CH2), 1.48 (t, J 5 7.0
Hz, 4H, CH2) 1.40–1.24 (m, 24H, CH2). 13C NMR (101 MHz,
CDCl3, d): 158.3 (C@O), 139.3 (C11), 114.3 (C12), 40.9 (C2),
33.9 (C10), 30.4 (C3), 29.7 (C8), 29.6 (C7), 29.5 (C5), 29.3
(C6), 29.1 (C9), 27.1 (C4). HRMS (ESI, m/z): [M 1 Na]1 calcd
for C23H44N2O, 387.3346; found, 387.3049; [M 1 H]1 calcd
for C23H44N2O, 365.3526; found, 365.3292.
DAP-uP-Bn-16 (6g): 1H NMR (400 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.24–7.14 (m, 10H, CH), 7.14–6.99 (m,
2H, CH), 5.89–5.71 (m, 2H, @CH), 5.41–5.26 (m, 2H, @CH),
5.01 (s, 4H, CH2) 4.98–4.85 (m, 4H, @CH2), 2.35–2.15 (m,
4H, CH2), 2.06–1.86 (m, 8H, CH2), 1.69–1.51 (m, 4H, CH2),
1.38–1.12 (m, 28H, CH2). 13C NMR (126 MHz, CDCl3, d):
173.6 (C@O), 154.1 (C3), 139.7 (C22), 137.7 (C1), 130.4
(C14), 130.0 (C12), 128.6 (C16), 127.7 (C15), 127.3 (C17),
119.0 (C2), 114.3 (C23), 51.0 (C13), 35.3 (C5), 32.7 (C21),
29.9 (C11), 29.8 (C7), 29.5 (C10), 29.4 (C8), 29.4 (C18), 29.3
(C9), 29.2 (C20), 29.1 (C19), 25.5 (C6).
Polymerization
The polymerizations were carried out under an atmosphere
of nitrogen as bulk polymerization.54 A Schlenk tube was
filled with the monomers (1a–c, 2a–f or 5) and the appro-
priate amount of Grubbs’ 1st generation catalyst (250:1
monomer to catalyst ratio) was transferred to the Schlenk
tube under a counterflow of nitrogen. The reaction mixture
was heated up to 65 8C in case of the protected monomers
(2a–f) or up to 130 8C in case of the unprotected monomers
(1a–f, 5), followed by the application of vacuum (p ꢁ3
mbar) to remove the generated ethylene. After the evolution
of ethylene stopped and the magnetic stir bar was unable to
move due to the increased viscosity the polymerization was
quenched by opening the Schlenk tube. The crude polymer
was dissolved in a small amount of THF and precipitated
into cold methanol to remove unreacted monomer and resid-
ual catalyst and was obtained as white to beige solid in
yields ranging from 73 to 97%. Polymers 6a–c and 8 could
DAP-uP-Bn-18 (6h): 1H NMR (500 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.24–7.14 (m, 10H, CH), 7.10 (d, J 5 6.7
Hz, 2H, CH), 5.87–5.72 (m, 2H, @CH), 5.42–5.27 (m, 2H,
@CH), 5.08–4.86 (m, 8H, @CH2), 2.23 (t, J 5 7.0 Hz, 4H, CH2),
2.04–1.88 (m, 8H, CH2), 1.68–1.52 (m, 4H, CH2), 1.37–1.10
(m, 28H, CH2). 13C NMR (126 MHz, CDCl3, d): 173.6 (C@O),
154.1 (C3), 139.8 (C22), 137.7 (C1), 130.5 (C13), 130.0
(C17), 128.6 (C16), 127.3 (C18), 119.0 (C2), 50.9 (C14), 35.3
(C5), 32.8 (C12), 29.9 (C8), 29.8 (C7), 29.6 (C11), 29.5 (C9*),
29.5 (C19), 29.5 (C20), 29.3 (C10), 29.2 (C9), 27.4 (C6).
DAP-uP-Bn-20 (6i): 1H NMR (500 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.24–7.16 (m, 10H, CH), 7.10 (d, J 5 6.5
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Hz, 2H, CH), 5.91–5.68 (m, 2H, @CH), 5.46–5.21 (m, 2H,
@CH), 5.10–4.79 (m, 4H, @CH2), 2.23 (t, J 5 7.0 Hz, 4H, CH2),
2.07–1.88 (m, 8H, CH2), 1.70–1.43 (m, 4H, CH2), 1.38–1.11
(m, 32H, CH2). 13C NMR (126 MHz, CDCl3, d): 173.6 (C@O),
154.1 (C3), 139.7 (C23), 137.7 (C1), 130.5 (C16), 130.0
(C14), 128.6 (C18), 127.7 (C17), 127.3 (C19), 119.0 (C2),
51.0 (C15), 35.3 (C5), 33.9 (C22), 32.8 (C13), 29.9 (C10),
29.8 (C7), 29.6 (C8), 29.6 (C12), 29.6 (C20), 29.5 (C11), 29.4
(C9), 29.4 (C21), 25.5 (C6).
DAP-sP-Bn-18 (7h): 1H NMR (400 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.24–7.14 (m, 10H, CH), 7.10 (d, J 5 6.3
Hz, 2H, CH), 5.01 (s, 4H, CH2), 2.23 (t, J 5 7.2 Hz, 4H, CH2),
1.66–1.50 (m, 4H, CH2), 1.44–1.06 (m, 40H, CH2), 0.95–0.77
(m, 6H). 13C NMR (101 MHz, CDCl3, d): 173.6 (C@O), 154.1
(C3), 139.7 (C1), 137.7 (C13), 128.6 (C15), 127.7 (C14),
127.3 (C16), 119.0 (C2), 51.0 (C12), 35.3 (C5), 29.9 (C8),
29.9 (C7), 29.8 (C10), 29.7 (C11), 29.6 (C17), 29.5 (C9), 25.5
(C6).
DAP-sP-Bn-20 (7i): 1H NMR (500 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.25–7.15 (m, 10H, CH), 7.14–6.98 (m,
2H, CH), 5.01 (s, 4H, CH2), 2.23 (t, J 5 7.2 Hz, 4H, CH2),
1.64–1.49 (m, 4H, CH2), 1.34–1.09 (m, 48H, CH2), 0.92–0.76
(m, 6H, CH3). 13C NMR (126 MHz, CDCl3, d): 173.6 (C@O),
154.1 (C3), 139.7 (C1), 137.7 (C13), 128.6 (C15), 127.7
(C14), 127.3 (C16), 119.0 (C2), 51.0 (C12), 35.3 (C5), 29.9
(C19), 29.9 (C8), 29.9 (C7), 29.8 (C10), 29.7 (C11), 29.6
(C17), 29.5 (C18), 29.4 (C9), 25.5 (C6), 21.0 (C20), 14.3
(C21).
Hydrogenation
A one-necked flask was filled with the appropriate polymer
6a–i or 8 (1 eq.), p-toulenesulfonhydrazide (TsNHNH2) (4
eq. according to the amount of double bonds), N,N-diisopro-
pylethylamine (2.7 eq.), and N,N-dimethylformamide (DMF)
(10 mL). The reaction mixture was flushed with nitrogen for
30 min and was heated to 150 8C for 6 h under vigorous
stirring. After cooling to room temperature the solvent was
removed in vacuum at 45 8C, followed by the addition of
THF in order to dissolve the crude product. The final poly-
mer was obtained by precipitation into cold methanol as a
beige solid in yields ranging from 68 to 94%.
RESULTS AND DISCUSSION
ADMET polymerization and subsequent hydrogenation were
used to synthesize various precision polymers (7a–i and 9)
bearing the different functional groups (DAP and urea)
along the polymer backbone. DAP and urea moieties were
incorporated into the polyethylene backbone via specially
designed symmetrical monomers. These planar groups are
able to act as fold-inducing element on the polymer chain
due to their conformation and are able to interact via
supramolecular interactions (p–p-stacking and hydrogen
bonding), thus influencing the final crystalline morphology.
By variation of the alkyl chain length of the monomer the
position of the functional group in the polymer backbone
can be determined precisely, whereby precision polymers
bearing this defect after every 16th, 18th, or 20th carbon
were obtained. In this article, we are examining the effect
of different supramolecular interactions between adjacent
polymer chains on the chain packing and crystallization of
precision polymers.
DAP-sP-Me-16 (7d): 1H NMR (500 MHz, CDCl3, d): 7.75 (t,
J 5 7.9 Hz, 1H, CH), 7.24 (d, J 5 5.6 Hz, 2H, CH), 3.36 (s, 6H,
CH3), 2.36 (t, J 5 7.5 Hz, 4H, CH2), 1.70–1.51 (m, 4H, CH2),
1.34–1.13 (m, 36H, CH2), 0.96–0.75 (m, 6H, CH3). 13C NMR
(126 MHz, CDCl3, d): 173.8 (C@O), 155.0 (C3), 139.8 (C1),
117.7 (C2), 35.4 (C12), 35.3 (C5), 32.0 (C14), 29.8 (C8), 29.8
(C7), 29.8 (C10), 29.7 (C11), 29.6 (C13), 29.5 (C9), 25.5
(C6), 22.8 (C15), 14.3 (C16).
DAP-sP-Me-18 (7e): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 7.8 Hz, 1H, CH), 7.24 (d, J 5 7.1 Hz, 2H, CH), 3.36 (s, 6H,
CH3), 2.35 (t, J 5 7.5 Hz, 4H, CH2), 1.72–1.53 (m, 4H, CH2),
1.23 (bs, 40H, CH2), 0.86 (t, 6H, J 5 6.7 Hz). 13C NMR (101
MHz, CDCl3, d): 173.7 (C@O), 155.0 (C3), 139.8 (C1), 117.7
(C2), 35.4 (C12), 35.3 (C5), 32.0 (C14), 29.8 (C8), 29.8 (C7),
29.8 (C10), 29.7 (C11), 29.6 (C13), 29.5 (C9), 25.5 (C6), 22.8
(C15), 14.2 (C16).
DAP-sP-Me-20 (7f): 1H NMR (400 MHz, CDCl3, d): 7.75 (t,
J 5 8.0 Hz, 1H, CH), 7.24 (d, J 5 8.4 Hz, 2H, CH), 3.36 (s, 6H,
CH3), 2.39–2.32 (m, 4H, CH2), 1.68–1.58 (m, 4H, CH2), 1.32–
1.15 (m, 48H, CH2), 0.87 (t, J 5 6.8 Hz, 6H, CH3). 13C NMR
(101 MHz, CDCl3, d): 173.7 (C@O), 155.0 (C3), 139.8 (C1),
117.7 (C2), 35.4 (C12), 35.3 (C5), 32.1 (C15), 29.9 (C8), 29.9
(C7), 29.8 (C10), 29.8 (C11), 29.7 (C13), 29.6 (C14), 29.5
(C9), 25.5 (C6), 22.8 (C16), 14.3 (C17).
Monomer Synthesis
The required monomers 1a–c, 2a–f, and 5 bearing a DAP
unit were synthesized as mentioned previously51 in a Schot-
ten–Baumann reaction using DCM and water as solvent and
NaOH as base, whereby acid chlorides with different alkyl
chain lengths (x 5 7, 8, 9) and DAP were chosen as precur-
sors. Subsequently, the free amide groups were protected by
the reaction of the unprotected monomers 1a–c with either
methyl iodide or benzyl bromide to sustain the solubility of
the compounds after polymerization (see Scheme 1). All DAP
monomers (1a–f, 2a–f) were analyzed via 1H and 13C NMR
spectroscopy as well as ESI-ToF MS and the corresponding
spectra are shown in Supporting Information Figures S1–S9.
The assignment of all resonances was possible and con-
firmed the purity of all compounds. The synthesis of mono-
mer 5, bearing a urea group, was accomplished in the first
step by the reaction of undec-9-enoyl chloride with
DAP-sP-Bn-16 (7g): 1H NMR (400 MHz, CDCl3, d): 7.60 (t,
J 5 7.9 Hz, 1H, CH), 7.24–7.12 (m, 10H, CH), 7.09 (d, J 5 6.5
Hz, 2H, CH), 5.01 (s, 4H, CH2), 2.23 (t, J 5 7.1 Hz, 4H, CH2),
1.66–1.49 (m, 4H, CH2), 1.21 (bs, 40H, CH2), 0.86 (t, J 5 6.8
Hz, CH3). 13C NMR (101 MHz, CDCl3, d): 173.6 (C@O), 154.1
(C3), 139.8 (C1), 137.7 (C13), 128.6 (C15), 127.7 (C14),
127.3 (C16), 119.0 (C2), 51.0 (C12), 35.3 (C5), 29.8 (C8),
29.8 (C7), 29.7 (C10), 29.6 (C11), 29.5 (C9), 25.5 (C6), 21.2
(C19).
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FIGURE 1 13C NMR spectra of undec-10-enamide (3) (top), undec-10-en-1-amine (4) (middle), and 1,3-diundec-10-en-1-ylurea (5)
(bottom). [Color figure can be viewed at wileyonlinelibrary.com]
ammonium hydroxide yielding undec-10-enamide (3) as a
white solid. Successful conversion was proven by the shift of
the signal assigned to the carbonyl group from 174.1 ppm to
175.9 ppm as well as the shift of signal belonging to the
adjacent CH2 group from 46.9 ppm to 36.1 ppm in the 13C
NMR spectrum as shown in Figure 1 (top). Via subsequent
reduction of compound 3 with LiAlH4 in dry THF at 0 8C
undec-10-en-1-amine (4) could be obtained, resulting in the
disappearance of the signal of the carbonyl group in the 13C
NMR spectrum (Fig. 1 middle). In a final step this amine was
then reacted with ethylene carbonate under use of 1,5,7-tria-
zabicyclo[4.4.0]dec-5-ene (TBD) as organocatalyst without
any solvents at 130 8C. The purity of the obtained precursors
(3 and 4) as well as the urea-monomer (5) was proven via
1H and 13C NMR spectroscopy as well as ESI-ToF MS (see
Supporting Information Figs. S10–S14). All resonances can
clearly be assigned and especially the carbonyl function
(158.5 ppm) and the allylic carbons (139.3 and 114.3 ppm)
shown in Figure 1 (bottom) prove the complete conversion
into the symmetrical urea. The reaction scheme for the
monomer syntheses as well as the polymerization and subse-
quent hydrogenation is shown in Scheme 1.
polymerization temperature.54 Grubbs’ 1st generation cata-
lyst has been demonstrated as an advantageous catalyst for
ADMET due to its relatively high stability and low isomeriza-
tion rate. Although, the reaction was not quenched with ethyl
vinyl ether as usual55 both NMR analysis and MALDI ToF MS
showed that no residual catalyst, neither attached to the
polymer chain nor as impurity, was present. The successful
conversion can be proven by the occurrence of the olefinic
1
signals in the H and 13C NMR spectra in the range of 5.31–
5.38 ppm and 130 ppm, respectively (see Supporting Infor-
mation Figs. S15–S18), which can be assigned to the newly
developed internal double bonds.30,56,57
The obtained molecular weights and associated polydisper-
sity indices are listed in Table 1. The polymers without pro-
tection group (6a–c and 8) could not be characterized by
SEC and NMR spectroscopy due to their insolubility in any
tested solvent presumably caused by the formation of hydro-
gen bonds and the segregation from the saturated alkyl
chains. Therefore, in these cases (polymers 6a–c and 8) the
progress of polymerization was monitored via IR spectros-
copy, monitoring the characteristic absorption bands of the
monomers (1c and 5) at ꢁ911 and ꢁ991 cm21, which rep-
resent the CAH out-of-plane deformation vibration of the
vinylic end groups. After polymerization the intensities of
these bands are decreased and a new band at ꢁ963 cm21
becomes apparent, which is related to CAH out-of-plane
Polymerization
All polymerizations were carried out as bulk polymerizations
as the used monomers (1a–c, 2a–f, and 5) are either viscous
liquids or present in the molten state at the chosen
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TABLE 1 Molecular Weights and Thermal Properties of the Synthesized DAP (6a–i, 7a–i) and Urea Polymers (8, 9)
a
b
Functional
Group
Mn
Mn
DHm
(J g21
Polymer
(g mol21
)
(g mol21
)
PDI
Tg (8C)
Tm (8C)
Tc (8C)
)
DT (8C)
Xc (%)
c
c
6a
6b
6c
7a
7b
7c
–
–
–
–
–
–
123.3
137.7
123.3
167.7
167.8
154.8
108.3
118.7
95.9
59.99
53.94
47.99
73.06
55.20
57.07
15.0
19.0
27.4
28.0
29.0
26.1
27
23
19
32
24
23
139.7
138.8
128.7
6d
6e
6f
4250
3640
8980
3880
4320
6380
20,520
4970
9200
2272
2800
8310
1.6
1.5
1.8
1.4
1.3
1.8
–16.8
–
–
–
–
–
–
–
–
–
–
57.1
62.3
89.2
86.2
96.3
–
36.05
32.90
73.70
80.57
45.68
–
21
17
33
35
18
–7.3
38.6
41.3
63.6
69.6
50.6
44.9
32.7
7d
7e
7f
6g
6h
6i
2720
4370
9890
4430
7460
10,000
c
7680
29,850
20,510
8200
8630
9930
c
2.2
2.1
2.1
1.6
1.4
1.9
–7.7
–10.1
–8.6
–8
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
7g
7h
7i
–
–
–
–
–
–2.2
–
–
–
–
–
–
15.0
9.3
28.83
5.7
12
8
9
–
–
116.0
125.0
85.0
94.6
32.44
58.81
31.0
30.4
13
24
a
c
Determined by SEC analysis in THF using polystyrene calibration.
Determined by NMR analysis.
Determination of the molecular weight and the molecular weight dis-
tribution was not possible due to insolubility of the samples.
b
vibration of the newly formed internal C@C double bonds18
(see the corresponding IR spectra in Figure 2 and Support-
ing Information Fig. S19).
terminal methyl groups (0.85–0.88 ppm) in the 1H NMR
spectra (see Supporting Information Fig. S20). The unsatu-
rated polymers without protection groups (6a–c and 8)
were subjected to the same method, proving completion of
the hydrogenation of the polymers 6a–c and 8 via IR spec-
troscopy by the disappearance of the absorption band at
ꢁ963 cm21 (see Fig. 2 and Supporting Information Fig. S19).
All DAP polymers with methyl protection group (6d–f and
7d–f) were also characterized by MALDI-ToF MS and the
corresponding spectra are shown in Figure 3 as well as Sup-
porting Information Figures S21 and S22.
Hydrogenation
The hydrogenation of the polymers was achieved by the
reaction with TsNHNH2 and N,N-diisopropylethylamine in
DMF at 150 8C for 6h, which already turned out to be a suc-
cessful method,51,57–59 proving the completeness to the fully
saturated polymers (7d–i) by the disappearance of all ole-
finic signals (from 4.90 to 5.84 ppm) and the formation of
All polymers show a mass distribution from 1200 to 7000
g mol21. One to three different series can be assigned,
whereby the main series always shows our linear polymers
(6d–f, 7d-f) as Li adducts. The other series indicate the frag-
mentation of our polymers due to the relatively high laser
energy required for desorption during the MALDI process.
The distance between two peaks of each series accounts
from ꢁ413 g mol21 to ꢁ471 g mol21, which is indicative for
the corresponding repetitive DAP unit containing 16 to 20
alk(en)yl units.
Thermal Analysis
The thermal behavior of all synthesized polymers was deter-
mined via DSC measurements. Selected heating curves,
derived from the second heating run, are shown in Figure 4.
FIGURE 2 Infrared spectra of the unprotected DAP monomer
(1c) as well as the resulting unsaturated (6c) and saturated (7c)
polymer. [Color figure can be viewed at wileyonlinelibrary.com]
All benzyl protected polymers (6g–i and 7g,h), except 7i are
amorphous, showing no melting point but only a glass
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turn enabling the formation of alkyl-crystals.57 If an N-
methyl protection group is used instead, only the unsatu-
rated polymer with the shortest methylene spacer length
(6d) shows no crystallinity, whereas all of the other methyl
protected polymers (6e–f) show crystallinities in the range
of 17–35%. Removing the methyl protection group (poly-
mers 6a–c) leads to an increase in melting temperature
from 123 up to 138 8C, certainly by the hydrogen bonding
between the DAP units, thus enhancing the thermal stability
of this polymers. A similar behavior was also observed for
diketopiperazine (DKP) functionalized polyethylenes, also
capable of hydrogen bonding.55 A significant structural dif-
ference between these DKP and our DAP polymers lies in
the substitution position of the defects. Thus, the para-
substituted DKP moieties can be included more easily into
the all-trans PE-chain compared to our meta-substituted DAP
moieties. This leads, in combination with the higher number
of H-bonds between adjacent polymer chains (DKP 5 4 H-
bonds, DAP 5 2 H-bonds), to higher melting points. The poly-
mer bearing a urea group (8) also shows melting at elevated
temperatures (Tm 5 116 8C), explained by supramolecular
interactions between adjacent functional groups. Hydrogena-
tion of the samples (polymers 7a–f, 9) leads to an increase
in melting temperatures of about 30 8C and slightly
increased crystallinities compared to the non-hydrogenated
polymers 6a–f and 8 [see Fig. 4(b)].
FIGURE 3 MALDI-ToF mass spectra of the non-hydrogenated
(6e) and hydrogenated (7e) DAP-polymers with methyl protec-
tion group and a methylene spacer length of n 5 18.
The unprotected DAP-polymers (7a–c) exhibit melting tem-
peratures, that are above the Tm of pure ADMET polyethyl-
ene (Tm 5 134 8C),39 explainable by enhanced thermal
stability due to hydrogen bonds, comparable to polymers
bearing sulfone groups along the polyethylene backbone as
demonstrated in literature.30 The observed cold crystalliza-
tion apparent in every melting endotherm of the protected
DAP polymers (6d–f and 7d–f) can be interpreted as an at
least partial incorporation of the functional group into the
crystalline lamella, as the additional high supercooling
(DT 5 32–69 8C) implies a slower crystallization rate, similar
to observations for other precision polymers.37,44,58 Super-
cooling decreases for the DAP polymers without protection
transition in the range of 210 to 22 8C (Supporting Infor-
mation Fig. S23). Only the fully hydrogenated polymer with
the longest methylene spacer length (7i, solid green curve)
shows a small endotherm in the heating curve indicating a
12% crystallinity and a melting temperature of 15 8C,
explainable by the size of the benzyl protection group, which
is too big to be incorporated into the crystal and thus hin-
ders crystallization, compensated only by an increasing chain
length of the alkyl chain in between the functional groups, in
FIGURE 4 DSC heating curves (second heating run) of the (a) unsaturated polymers (6a–f and 8) and the (b) saturated polymers
(7a–f and 9). [Color figure can be viewed at wileyonlinelibrary.com]
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Characteristic for all samples is a (001) reflection in the
range 2.4 < q < 2.8 nm21, corresponding to lattice planes
indicating the distance between two DAP-units along the
chain. The presence of a higher order reflection (002) at
4.8 < q < 5.6 nm21 indicates a lamellar morphology, also
observed for precision sulfone polyethylenes.30 The (001)
reflection as well as the second order peak (002) shifts sys-
tematically to higher q values (corresponding to lower dis-
tances according to Bragg’s law
d
hkl 5 2p/qhkl
)
with
decreasing methylene spacer length. All diffraction patterns
show a signal at 8.9 nm21, which is independent from the
methylene spacer length and thus represents the periodicity
along one of the two lateral directions, presumably assigned
to the distance between two DAP-units of adjacent polymer
chains. These signals can be assigned to the (100) reflexes,
whereby the corresponding second order peaks (200) with
calculated distances of 0.35–0.36 nm represent the expected
p–p-interactions between the DAP-units, which are proven to
be in the range of 0.33–0.38 nm,60 indicating a parallel
arrangement of the DAP-units of adjacent polymer chains.
The
broad
signal
in
the
wide
angle
range
(14 ꢂ q ꢂ 16 nm21), which is also independent from the
methylene spacer length, can be assigned to the (110) reflex
of an orthorhombic unit cell.58,61 A closer inspection of the
lamellar spacings calculated from the (001) diffraction peaks
give d001 values of about 2.24 nm for a spacer length of
n 5 16 (7d), 2.44 nm for n 5 18 (7e), and 2.64 nm for
n 5 20 (7f), respectively. A linear dependence is observed if
these distances are plotted as a function of the number of
methylene units n [Fig. 5(b)]. An extrapolation of the d001
spacings to n 5 0 gives an intercept at about 6.3 Å, which
corresponds to the size of the DAP layer in the lamellar
structure. This value is close to theoretically calculated val-
ues for the size of a DAP group. Note that the linear depen-
dence of the lamellar spacing d001 on the number of CH2
units n is a common feature which is commonly found for
related polymers with linear methylene spacer in the main
chain and also obtained for nanophase-separated comb-like
polymers with lamellar morphology such as alkoxylated pol-
yesters,62 alkoxylated polyphenylene vinylenes,63 and regio-
regular poly(3-alkyl thiophenes)9 wherein methylene sequen-
ces are part of the side chains. A slope of 1 Å per CH2 is
observed for saturated DAP-polymers which is less than the
ideal slope of 1.25 Å per CH2 expected for fully extended
and interdigitated methylene sequences in the all-trans state
without tilting. This indicates that there are features in satu-
rated DAP polymers which are most likely a consequence of
constraints caused by the DAP units.
FIGURE 5 (a) X-ray diffraction patterns of the saturated DAP
polymers with methyl protection group and varying methylene
spacer lengths (7d–f). (b) Plot of lamellar spacing d001 calcu-
lated based on Bragg’s law as a function of methylene spacer
length. [Color figure can be viewed at wileyonlinelibrary.com]
group 7a–c (DT 5 15–30 8C) as well as for the polymer bear-
ing a urea group 9 (DT 5 31 8C), indicating the facilitated
inclusion of the defects into the crystalline lamella. In the
heating curves of the saturated polymers 7a–c and 9 pre-
dominantly two melting endotherms (in the case of 7c even
a melting-recrystallization) are visible, suggestive of the for-
mation of different polymorphs, similar to observations of
polyethylene bearing a para-phenylene ether group along the
polymer backbone.58 All thermal data are listed in Table 1.
Structural Analysis
Protected DAP Polymers (7d–f)
Crystal Structure Comparison of the Unprotected (7c) and
Protected (7f) DAP Polymers and the Urea Polymer (9)
To compare the influence of different supramolecular inter-
actions on the crystal structure, WAXS patterns of the unpro-
tected (7c) and protected (7f) DAP-polymers as well as the
urea polymer (9) with a methylene spacer length of n 5 20
were recorded after annealing them at 40 8C. The resulting
diffraction patterns are shown in Figure 6. After annealing
polymer 7f shows a better resolved diffraction pattern. The
Structural details of a series of saturated DAP polymers with
methyl protection group and varying number of methylene
units (n 5 16, 18, and 20) (7d–f) in the methylene spacer
are initially studied as representative example by wide angle
X-ray diffraction (WAXD). The experiments are aimed to
understand the influence of different spacer lengths and dif-
ferent chemical entities on the overall crystalline state [Fig.
5(a)].
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TABLE 2 Unit Cell Parameters and Lamellar Crystal Thick-
nesses of the Saturated DAP Polymers (7d–f)
appearance of additional peaks in the wide angle range indi-
cate the formation of a mixture of orthorhombic and triclinic
crystal structures, also observed for precision polymers con-
taining meta-substituted phenylenes.58 By assigning the
Code
a (nm)
b (nm)
c (nm)
lc (nm)
7d
7e
7f
0.71
0.71
0.71
0.55
0.55
0.54
2.24
2.44
2.64
8.42
12.11
9.65
reflexes to the corresponding planes of an orthorhombic
crystal cell (for 7d–f), the calculation of the unit cell parame-
ters, listed in Table 2, was possible.
The comparison of this parameters with those of orthorhom-
bic PE (a 5 0.74 nm, b 5 0.49 nm)39,64 shows a certain dila-
tion of the unit cell in the direction of the b-axis. The X-ray
diffraction pattern of the unprotected DAP-polymer 7c [see
Fig. 6(b)] also features two peaks in the low angle range,
which represent the distance in the c-direction and can be
assigned to the (001) and (002) reflex indicating the preser-
vation of the lamellar morphology. Remarkable here is the
disappearance of the signal at 8.9 nm21, which indicates that
the DAP-units are not arranged parallel to each other any-
more. The polymer containing a urea-group (9) shows nearly
the same diffraction pattern as the DAP-polymer without
protection groups (7c) [see Fig. 6(c)]. The signals at 2.7 and
5.4 nm21 in the small angle range represent the (001) and
(002) plane, thus implying a lamellar morphology, which
was also observed in low-molecular weight urea-compounds
interacting via hydrogen-bonding.65 Another indication for
the inclusion of the functional groups into the crystalline
lamella (beside the dilation of the unit cell) is the lamellar
thickness, which was calculated with the help of the
Scherrer-equation (eq 2) given below
K ꢀ k
lc5
(2)
Dð2hÞ ꢀ cos hhkl
where D(2h) is the full peak width at half maximum height
(FWHM), K ꢁ1 is the dimensionless Scherrer constant,
k 5 0.154 nm is the wavelength of the used Cu-Ka radiation,
and hhkl is a Bragg angle of the relevant reflection.
If the functional group would be excluded from the crystal
the lamellar crystal thickness would be equivalent to the
length of the corresponding CH2-chain. Assuming an all-trans
geometry we would expect a length of 1.88 nm for the C16-
chain, 2.13 nm for C18, and 2.38 nm for C20. All of the cal-
culated values for the lamellar crystal thickness, which range
between 9.42 and 12.11 nm (see Table 2) exceeded these
values, which further hints toward the inclusion of 3–5 func-
tional groups into one crystal lamella.
CONCLUSIONS
Series of polymers consisting of long methylene sequences
with different functional groups (defects) placed at precisely
regular intervals along the linear chain were synthesized via
ADMET polymerization and subsequent hydrogenation using
FIGURE 6 X-ray diffraction patterns of the annealed (a) DAP
polymer with methyl protection groups 7f, (b) the DAP polymer
without protection groups 7c, and (c) the urea polymer 9.
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18 G. Rojas, B. Inci, Y. Wei, K. B. Wagener, J. Am. Chem. Soc.
2009, 131, 17376.
TsNHNH2. By using Grubbs’ 1st generation catalyst polymers
with molecular weights ranging from 2700 to 10,000
g mol21 and polydispersity indices between 1.3 and 2.2
were obtained in good yields (68–97%). The thermal proper-
ties of all polymers (6a–i, 7a–i, 8, 9) were investigated via
DSC analysis, whereby the unprotected DAP polymers (7a–c)
displayed melting temperatures, that are above pure ADMET-
PE, explainable by enhanced thermal stability due to hydro-
gen bonds. The structure of selected polymers was analyzed
19 M. D. Schulz, K. B. Wagener, Macromol. Chem. Phys. 2014,
215, 1936.
20 K. B. Wagener, J. T. Patton, Macromolecules 1993, 26, 249.
21 D. W. Smith, K. B. Wagener, Macromolecules 1993, 26, 1633.
22 J. E. O’Gara, J. D. Portmess, K. B. Wagener, Macromole-
cules 1993, 26, 2837.
23 J. T. Patton, J. M. Boncella, K. B. Wagener, Macromolecules
1992, 25, 3862.
using WAXD techniques.
A lamellar morphology was
24 K. Brzezinska, K. B. Wagener, Macromolecules 1992, 25,
2049.
observed for all the investigated polymers. Investigations on
annealed samples of the saturated DAP polymer with 20 CH2
units per methylene sequence indicated an orthorhombic
unit cell, wherein the defects are at least partially included
into the crystalline region.
25 K. B. Wagener, D. W. Smith, Macromolecules 1991, 24,
6073.
26 K. B. Wagener, K. Brzezinska, Macromolecules 1991, 24,
5273.
27 P. Atallah, K. B. Wagener, M. D. Schulz, Macromolecules
2013, 46, 4735.
28 J. Mandal, S. Krishna Prasad, D. S. S. Rao, S.
Ramakrishnan, J. Am. Chem. Soc. 2014, 136, 2538.
ACKNOWLEDGEMENTS
The authors grateful acknowledge the grant within the Sonder-
forschungsbereich SFB TRR 102 (Polymers under multiple con-
straints) (SR, WHB, Project A03) and (VD, MB, Project A15).
Authors also thank Dr. Ute Baumeister, Matthias Fischer, and
Nasir Mahmood for providing WAXS measurements.
29 M. Pulst, M. H. Samiullah, U. Baumeister, M. Prehm, J.
Balko, T. Thurn-Albrecht, K. Busse, Y. Golitsyn, D. Reichert, J.
Kressler, Macromolecules 2016, 49, 6609.
30 T. W. Gaines, E. B. Trigg, K. I. Winey, K. B. Wagener, Macro-
mol. Chem. Phys. 2016, 217, 2351.
31 J. K. Leonard, Y. Wei, K. B. Wagener, Macromolecules 2011,
45, 671.
32 J. K. Leonard, T. E. Hopkins, K. Chaffin, K. B. Wagener, Mac-
romol. Chem. Phys. 2008, 209, 1485.
REFERENCES AND NOTES
€
1 R. M. Michell, A. T. Lorenzo, A. J. Muller, M.-C. Lin, H.-L.
33 G. Ungar, X-B. Zeng, Chem. Rev. 2001, 101, 4157.
34 K. Yokota, Prog. Polym. Sci. 1999, 24, 517.
ꢀ
Chen, I. Blaszczyk-Lezak, J. Martın, C. Mijangos, Macromole-
cules 2012, 45, 1517.
35 J. C. Sworen, J. A. Smith, K. B. Wagener, L. S. Baugh, S. P.
Rucker, J. Am. Chem. Soc. 2003, 125, 2228.
ꢀ
2 J. Martın, J. Maiz, J. Sacristan, C. Mijangos, Polymer 2012,
53, 1149.
36 H. S. Bazzi, H. F. Sleiman, Macromolecules 2002, 35, 9617.
3 H. Duran, M. Steinhart, H.-J. Butt, G. Floudas, Nano Lett.
2011, 11, 1671.
37 M. D. Watson, K. B. Wagener, Macromolecules 2000, 33,
5411.
€
4 R. M. Michell, I. Blaszczyk-Lezak, C. Mijangos, A. J. Muller,
38 R. G. Alamo, L. Mandelkern, Thermochim. Acta 1994, 238, 155.
Polymer 2013, 54, 4059.
39 B. Inci, I. Lieberwirth, W. Steffen, M. Mezger, R. Graf, K.
Landfester, K. B. Wagener, Macromolecules 2012, 45, 3367.
€
5 R. M. Michell, A. J. Muller, Prog. Polym. Sci. 2016, 54–55,
183.
40 Y.-R. Zheng, H. T. Tee, Y. Wei, X.-L. Wu, M. Mezger, S. Yan,
K. Landfester, K. Wagener, F. R. Wurm, I. Lieberwirth, Macro-
molecules 2016, 49, 1321.
6 Y.-L. Loo, R. A. Register, A. J. Ryan, G. T. Dee, Macromole-
cules 2001, 34, 8968.
€
7 E. Hempel, H. Budde, S. Horing, M. Beiner, In Progress in
41 X.-H. Dong, R. Van Horn, Z. Chen, B. Ni, X. Yu, A. Wurm, C.
Schick, B. Lotz, W.-B. Zhang, S. Z. D. Cheng, J. Phys. Chem.
Lett. 2013, 4, 2356.
Understanding of Polymer Crystallization; Reiter, G., Strobl, G.
R., Eds.; Springer: Berlin, Heidelberg, 2007; pp 201–228.
8 T. Babur, G. Gupta, M. Beiner, Soft Matter 2016, 12, 8093.
9 S. Pankaj, M. Beiner, J. Phys. Chem. B 2010, 114, 15459.
10 M. Ballauff, Angew. Chem. Int. Ed. 1989, 28, 253.
42 K. E. Russell, D. C. McFaddin, B. K. Hunter, R. D. Heyding, J.
Polym. Sci. Part B: Polym. Phys. 1996, 34, 2447.
43 G. Lieser, G. Wegner, J. A. Smith, K. B. Wagener, Colloid
Polym. Sci. 2004, 282, 773.
11 R. G. Alamo, K. Jeon, R. L. Smith, E. Boz, K. B. Wagener, M.
R. Bockstaller, Macromolecules 2008, 41, 7141.
44 W. Qiu, J. Sworen, M. Pyda, E. Nowak-Pyda, A.
Habenschuss, K. B. Wagener, B. Wunderlich, Macromolecules
2005, 39, 204.
12 K. N. Bauer, H. T. Tee, I. Lieberwirth, F. R. Wurm, Macromo-
lecules 2016, 49, 3761.
13 P. Kaner, C. Ruiz-Orta, E. Boz, K. B. Wagener, M. Tasaki, K.
Tashiro, R. G. Alamo, Macromolecules 2013, 47, 236.
45 E. Boz, K. B. Wagener, A. Ghosal, R. Fu, R. G. Alamo, Mac-
romolecules 2006, 39, 4437.
14 K. L. Opper, B. Fassbender, G. Brunklaus, H. W. Spiess, K.
B. Wagener, Macromolecules 2009, 42, 4407.
46 M. Tasaki, H. Yamamoto, M. Hanesaka, K. Tashiro, E. Boz,
K. B. Wagener, C. Ruiz-Orta, R. G. Alamo, Macromolecules
2014, 47, 4738.
15 P. Ortmann, S. Mecking, Macromolecules 2013, 46, 7213.
16 G. Rojas, E. B. Berda, K. B. Wagener, Polymer 2008, 49,
2985.
47 E. Boz, A. J. Nemeth, K. B. Wagener, K. Jeon, R. Smith, F.
Nazirov, M. R. Bockstaller, R. G. Alamo, Macromolecules 2008,
41, 1647.
17 G. Rojas, K. B. Wagener, Macromolecules 2009, 42, 1934.
12
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2017, 00, 000–000

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ARTICLE
48 A. J. Heeger, J. Phys. Chem. B 2001, 105, 8475.
57 Z.-L. Li, L. Li, X.-X. Deng, L.-J. Zhang, B.-T. Dong, F.-S. Du,
Z.-C. Li, Macromolecules 2012, 45, 4590.
49 B. S. Ong, Y. Wu, P. Liu, S. Gardner, J. Am. Chem. Soc.
2004, 126, 3378.
58 S.-F. Song, Y.-T. Guo, R.-Y. Wang, Z.-S. Fu, J.-T. Xu, Z.-Q.
Fan, Macromolecules 2016, 49, 6001.
50 X. Fang, K. Liu, C. Li, J. Am. Chem. Soc. 2010, 132, 2274.
59 S. Kobayashi, L. M. Pitet, M. A. Hillmyer, J. Am. Chem. Soc.
2011, 133, 5794.
51 S. Reimann, U. Baumeister, W. H. Binder, Macromol. Chem.
Phys. 2014, 215, 1963.
60 C. Janiak, J. Chem. Soc. Dalton Trans. 2000, 3885–
3896.
52 C. Macleod, G. J. McKiernan, E. J. Guthrie, L. J. Farrugia, D.
W. Hamprecht, J. Macritchie, R. C. Hartley, J. Org. Chem. 2002,
68, 387.
61 B. Inci, K. B. Wagener, J. Am. Chem. Soc. 2011, 133, 11872.
53 F. Saliu, B. Rindone, Tetrahedron Lett. 2010, 51, 6301.
62 T. Babur, J. Balko, H. Budde, M. Beiner, Polymer 2014, 55,
6844.
54 H. Li, L. Caire da Silva, M. D. Schulz, G. Rojas, K. B.
Wagener, Polym. Int. 2017, 66, 7.
63 G. Gupta, V. Danke, T. Babur, M. Beiner, J. Phys. Chem. B
2017, 121, 4583.
55 K. Terada, E. B. Berda, K. B. Wagener, F. Sanda, T. Masuda,
Macromolecules 2008, 41, 6041.
64 M. Kobayashi, J. Chem. Phys. 1979, 70, 509.
56 F. Marsico, M. Wagner, K. Landfester, F. R. Wurm, Macro-
molecules 2012, 45, 8511.
65 M. George, G. Tan, V. T. John, R. G. Weiss, Chem.—Eur. J.
2005, 11, 3243.
WWW.MATERIALSVIEWS.COM
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