Novel fullerene-based porous materials constructed by a solvent knitting strategy

Article abstract of DOI:10.1039/c7cc06702j

Here we choose a dihydronaphthyl-functionalized C₆₀ fullerene as a building block and utilize a novel solvent knitting strategy based on Friedel-Crafts alkylation reaction to construct two kinds of novel porous materials by using dichloromethane (DCM) and 1,2-dichloroethane (DCE) as solvents and external crosslinkers. The resulting porous materials show relatively high apparent BET surface areas and gas uptake abilities.

Full text of DOI:10.1039/c7cc06702j

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Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc
first methanofullerene derivatives of Sc
3
N@C2n (2n
=
68 and 80). Synthesis of the
3
N@D5h-C80
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DOI: 10.1039/C7CC06702J
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Novel fullerene‐based porous materials constructed by solvent
kniꢀng strategy†
ab
ab
ab
Chengxin Zhang, Shaolei Wang and Bien Tan*
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
Here we choose a dihydronaphthyl‐functionalized C60 fullerene as increased worldwide attention. Considering these unique properties
building block and utilize a novel solvent knitting strategy based on and potential applications, many reports about C60 and its derivatives
2
5
have been published on fullerene-functionalized materials. Recently,
some porous polymers have been reported in combination with
fullerenes, which are usually synthesized by two strategies:
introducing fullerene into the porous frameworks by post
functionalization, or focused on building fullerene-derivatives based
porous materials. For example, Jiang et al. reported a novel electron
donor-acceptor COFs, of which 2D-skeletons were built from
electron-donating monomers and introduced the typical electron
acceptor, fullerene, within the open channels of frameworks via Click
chemistry.26 In 2016, Zhu et al. firstly reported a series of C60-based
PAFs materials combining both symmetrical conjugated structure of
Friedel‐Crafts alkylation reaction to construct two kinds of novel
porous materials by using dichloromethane(DCM) and 1,2‐
dichloroethane(DCE) as solvents and external crosslinkers. The
resulting porous materials show relatively high apparent BET
surface areas and gas uptake abilities.
Microporous organic polymers (MOPs) have attracted wide attentions
in many fields like gas storage and separation,1-3 catalysis,4, 5 chemical
sensing,6 energy storage and conversion,7 etc. Compared with
traditional inorganic porous materials, such as zeolites and activated
carbon, MOPs which consist purely of organic components have
many advantages such as low skeletal density, abundant pore structure
and easier functionalization,8,9 which further expands the scope of
applications of MOPs. Until now, many different kinds of MOPs,
which were classified by the structure and synthetic strategy, have
been reported, such as conjugated microporous polymers (CMPs),10,11
polymers of intrinsic microporosity (PIMs),12 covalent organic
frameworks(COFs),13,14 hyper-crosslinked polymers (HCPs),15,16
porous aromatic frameworks (PAFs).17 With a variety of synthetic
strategies and synthetic routes, a large number of molecules with
special functions can be synthesized and designed as building blocks
to construct novel porous materials with various specific functions
and applications. 9,18
C
60 and the porous properties of PAFs using external crosslinker
knitting method, which showed relatively high surface area of 1094
m2g-1 and a comparable adsorption capacity for H .27
and CO
2
2
It is well established that the pure fullerene C60 powder only possess
a certain solubility in several aromaticity solvents like toluene, but its
derivatives show decent solubility in common solvents like DCM and
DCE. Chemical functionalization of the fullerene cage has easily been
achieved to make fullerene derivatives and promote their involvement
in organic reactions. Recently, our group developed a novel solvent
knitting strategy employing AlCl
3
as Lewis acid catalyst, chloralkane
as solvents and external crosslinkers to knit HCPs materials.
2
8,29
This
simple, versatile and flexible method is very useful for “knitting”
aromatic compounds to construct HCPs materials with abundant
porosity and without any other additional effects on the structure of
building block compounds.
Herein, we employed a dihydronaphthyl-functionalized fullerene
NC60BA (N for abbreviation)30 , with excellent solubility, as the
building block to construct microporous C60-based polymers which
are named N-H-1 and N-H-2 by using DCM and DCE as solvent and
external crosslinking agent, respectively. The resulting porous
materials show high surface area, favourable gas adsorption capacity
and thermal stability, and they have been thoroughly characterized to
understand their structure and properties.
As a novel kind of three-dimensional aromatic compound with unique
cage structure, fullerene, which was first reported by Kroto et al,1
shows a variety of applications in many fields including those in solar
cells,20 semiconducting materials,21 electrochemical systems,22
catalysis,23 and biological medicine,24 and have thus attracted
9
a.
School of Chemistry and Chemical Engineering, Huazhong University of Science
and Technology, Wuhan, 430074, China. E‐mail: bien.tan@mail.hust.edu.cn; Tel:
+86 2787558172
b.
Key Laboratory for Large‐Format Battery Materials and System, Ministry of
Education, School of Chemistry and Chemical Engineering, Huazhong University of
Science and Technology, Luoyu Road No. 1037, Wuhan, 430074, China
Electronic supplementary information (ESI) available: NMR, CP/MAS NMR, TGA,
FSEM, HRTEM and isosteric heat of materials. See DOI: 10.1039/x0xx00000x
Although fullerenes have attracted much more attention due to vari-
†
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DOI: 10.1039/C7CC06702J
2 2 2
Scheme 1. The synthetic routes of the polymer networks (Red dots represent ‐CH ‐ or ‐CH ‐CH ‐)
ous applications, but, until now, there is not much focus on the (Fig. S3, ESI†).31,32 Compared with monomer, the intensity of
synthesis of C60 fullerene-based porous materials and their potential substituted aromatic carbon (140 ppm) and alkyl carbon peaks (40
applications. As shown in Scheme 1, we have prepared two novel C60 ppm) of HCPs increased, which was ascribed to much more alkyl
based porous materials using monomer N as building block by a linkers connected with monomer(Fig. S3 (b) (c), ESI†).33 These data
simple Friedel–Crafts reaction with two different external confirmed that the solvent knitting strategy has been succussfully
crosslinkers (Experimental details, ESI†). At the end of reaction, the employed for the construction of the HCPs materials.
solid insoluble products were obtained which were precipitated. In The thermal stability of monomer N, N-H-1 and N-H-2 was recorded
order to determine the structural features of the polymers, FT-IR and by thermogravimetric analysis (TGA). As shown in Fig. S4 (ESI†),
solid state 13C CP/MAS NMR were used for chemical characterization. the weight of N-H-1 and monomer N lost slowly and continuously,
o
The C–H stretching vibration bands of methylene linkage (ν -CH
2
-) and there was no significant loss of weight until 400 C for N-H-2,
near 2960–2800 cm-1 are evidently observed. Compared with which may be due to the difference in their chemical nature. Moreover,
monomer N, the weak signals of C-H stretching vibrations of the the introduction of alkyl leads to lower residual variability for N-H-1
aromatic ring (ν Ar-H) at 3100-3000 cm-1 disappeared after the and N-H-2.
crosslinking reactions for N-H-1 and N-H-2 , as shown in Fig.1. The The morphologies and porous textures of the two networks were
intensity of out-of-plane bending vibration peaks (γ Ar-H) at 910-665 investigated by field-emission scanning electron microscopy (FE-
-1
cm also reduced (Fig.1(b)) or even nearly vanished (Fig.1(c)), which SEM) and high-resolution transmission electron microscopy (HR-
suggests that most of the hydrogen atoms in benzene rings have been TEM) (Fig. S5, ESI†). The FE-SEM images revealed that the N-H-1
-1
replaced by methylene groups. The peak near 1425 cm clearly shows and N-H-2 showed an amorphous morphologies, and their structures
the original structure of fullerene is completely preserved.27 We are very similar. The HR-TEM images showed that there were
further investigated the chemical structure of the resulting materials abundant pore structure in both N-H-1 and N-H-2, which could be
by 13C CP/MAS NMR spectra (Fig.S3, ESI†). Two peaks are clearly
observed near 140 ppm and 130 ppm for monomer, which are
attributed to the substituted aromatic carbons and unsubstituted
2
8
aromatic carbons in the benzene rings respectively, and a narrow
3
peak around 60 ppm belongs to the sp fullerene carbons for monomer
Fig. 2 (a) (b)Nitrogen adsorption and desorption isotherms (77.3 K)
and (c) (d)pore size distribution calculated using DFT methods (slit
pore models, differential pore volumes) of N‐H‐1 (red) and N‐H‐2
(blue).
Fig. 1 The Fourier transform infrared (FT‐IR) spectra of monomer
N (a), N‐H‐1(b) and N‐H‐2(c).
2
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DOI: 10.1039/C7CC06702J
Fig. 3 The Volumetric CO
2
adsorption and desorption isotherms up to 1.13 bar at 273.15 K (a), 298.15 K (b) and volumetric H
2
adsorption isotherms and desorption isotherms up to 1.13 bar at 77.3 K (c) of N‐H‐1 and N‐H‐2.
Table 1 Porosity properties and gas uptake capacities of N‐H‐1 and N‐H‐2
[
a]
[b]
2
[c]
3
[d]
uptake[e]
uptake[f]
CO
2
uptake[g]
(wt %)
6.50
S
(
BET
S
L
PV
(cm g )
0.41
MPV
H
2
CO
2
No.
2
-1
-1
-1
3
-1
m g )
(m g )
(cm g )
0.25
(wt %)
0.92
0.55
[b]
(wt %)
10.59
7.51
N-H-1
N-H-2
753
235
997
317
0.22
0.05
4.91
[
a]
Surface area calculated from nitrogen adsorption isotherm at 77.3 K using BET equation. Surface area calculated from nitrogen adsorption isotherm at
7.3 K using Langmuir equation. [c] Pore volume calculated from nitrogen isotherm at P/P
=0.050.[e]
7
0
=0.995, 77.3 K. [d] Micropore volume calculated from the nitrogen
[f]
isotherm at P/P
0
H
2
uptake determined volumetrically using a Micromeritics ASAP 2020 M analyzer at 1.13 bar and 77.3 K. CO
2
uptake determined
volumetrically using a Micromeritics ASAP 2020 M analyzer at 1.13 bar and 273.15 K. [g] CO
ASAP 2020 M analyzer at 1.13 bar and 298.15K.
2
uptake determined volumetrically using a Micromeritics
observed clearly.
To better understand the pore characteristics, the porous nature of capacities of N-H-1 and N-H-2. As shown in Fig. 3a, the CO
polymers was further investigated by N sorption analysis at 77.3 isotherms of N-H-1 and N-H-2 are fairly consistent. Table 1 shows
K. As shown in Fig.S6, the BET surface of monomer N was nearly the values of CO
capture at di erent temperatures. The CO
m g , and there were almost no existence of micropores and uptake of N-H-1 and N-H-2 was found to be 10.59 wt% (2.41
2 2
therefore, we also set out to investigate CO and H absorptive
2
2
2
ff
2
2
-1
0
-
1
-1
mesopores (Fig.S6, ESI†
). However, the adsorption isotherms of mmol g ) and 7.51 wt% (1.48 mmol g ) at 273 K and 1.13 bar,
N-H-1 and N-H-2 exhibit a type I character with a high nitrogen respectively, which is comparable to that of CTF-FUMs and CTF-
-
1 36
gas uptake at low relative pressure (P/P
0
< 0.001), thus indicating DCNs (2.12-3.49 mmol g ), Cu(II)- and Ni(II)-PCPs (2.49-2.80
the abundant microporous structure,3 which are consistent with mmol g- ), HPPs (1.15-1.69 mmol g-1),38 POPSs (1.84-2.21
4,35
1 37
HR-TEM results. Moreover, the nitrogen adsorption and mmol g ), SHCPs (1.23-1.84 mmol g-1).40 Moreover, these
-1 39
desorption isotherms provide a strong evidence that the solvent values are higher than some materials with high surface areas such
2
-1
-1
41
knitting methods have been successful to construct porous as COF-102 (3620 m g ,1.52 mmol g at 273K and 1 bar), and
PAF-1 (5640 m2 g-1, 2.07 mmol g-1 at 273K and 1 bar).17
structures.
The BET surface area of N-H-1 and N-H-2 is up to 753 m g and Furthermore, the CO uptake of N-H-1 outperforms the
35 m2g-1 respectively. The pore size distribution of N-H-1 commercially available BPL carbon (2.09 mmol g ). Moreover,
2
-1
2
-1
42
2
showed hierarchical pores, in which the abundant micropores (0.8 N-H-1 exhibits not only the highest gas uptake capacity of these
nm) and continuous mesopores (less than 10 nm) are observed two porous networks, but also with a higher isosteric heat (Qst) of
clearly. From Table 1, the total pore volumes of N-H-1 and N-H- 25.49-21.28 KJ mol-1 (Fig. S8, ESI
†
). Based on the hydrogen
3
-1
3 -1
2
are 0.41 cm g and 0.22 cm g , respectively. It is obvious that sorption isotherms, we found that all isotherms were fully
the microporosity of N-H-1 (61%) is much higher than that of N- reversible and unsaturated at low pressures, and the hydrogen
H-2 (23%), which may be due to the difference in the length of uptake capacities reached up to 0.92 wt% and 0.55 wt% for N-H-
carbon chain (from DCM and DCE). DCM with shorter carbon 1 and N-H-2, respectively (Fig. 3(c)).
chain, made the monomers connected closely and formed a much In summary, we report a new kind of fullerene-based porous materials
more stable and tightly packed dense structure. The compact with abundant pore structure and good gas adsorption properties,
linking structure helps in constructing micropores and increasing which employs the fullerene derivatives as building blocks to
the surface area and pore volume. Based on the above analysis, the construct two different porous networks (N-H-1 and N-H-2) by using
solvent knitting method using DCM and DCE as the external a novel and relatively low-cost strategy. The pore characteristics of
crosslinker can e
ffectively link monomer N to obtain fullerene- these porous networks were calculated by surface area and porosity
based porous materials. Abundant porous structure make such analyzer. The resulting products show good absorption properties for
porous materials excellent gas absorbents for CO
2
and H
2
, and CO
2
and H
2
, thus making them promising candidates for applications
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in gas adsorption. By using the novel synthetic strategy, fullerene-
Smalley, Nature, 1985, 318, 162-163.
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based HCPs materials can be constructed using relatively mild 20. T. T. Cao, N. Chen, G. X. Liu, Y. B. Wan,DJO. DI: 1.0P.1e0re3a9,/CY7.CJC. X06i7a0, 2ZJ.
conditions, which makes the synthetic simple and more robust.
W. Wang, B. Song, N. Li, X. H. Li, Y. Zhou, C. J. Brabec and Y. F.
We thank the Analysis and Testing Centre, Huazhong University of
Li, J. Mater. Chem. A, 2017, 5, 10206-10219.
Science and Technology for assistance in characterization of materials. 21. M. H. Stewart, A. L. Huston, A. M. Scott, E. Oh, W. R. Algar, J.
This work was supported by the Program for National Natural Science
Foundation of China (no.21474033), the International S&T
Cooperation Program of China (2016YFE0124400), and the Program
for HUST Interdisciplinary Innovation Team (2016JCTD104).
R. Deschamps, K. Susumu, V. Jain, D. E. Prasuhn, J. Blanco-
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22. E. J. E. Stuart, K. Tschulik, C. Batchelor-McAuley and R. G.
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Conflicts of interest
23. J. Marco-Martinez, S. Reboredo, M. Izquierdo, V. Marcos, J. L.
Lopez, S. Filippone and N. Martin, J. Am. Chem. Soc., 2014, 136,
There are no conflicts to declare.
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