Visible-light-induced metathesis reaction between diselenide and ditelluride

Article abstract of DOI:10.1039/c9cc00252a

The Se-Te bond was prepared by a metathesis reaction between diselenides and ditellurides, which could be manipulated with the presence or absence of visible light. Additionally, the apparent activation energy of the exchange process was measured to be only 28.01 kJ mol^-1, explaining the high reactivity and sensitivity to light.

Full text of DOI:10.1039/c9cc00252a

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Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc3N@C2n (2n 68 and 80). Synthesis of the
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DOI: 10.1039/C9CC00252A
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Visible-Light-Induced Metathesis Reaction between Diselenide
and Ditelluride
Cheng Liu,a Jiahao Xia,a Shaobo Ji,a Zhiyuan Fan a and Huaping Xu *a
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
The Se-Te bond was prepared by a metathesis reaction between energy will lead to functional materials with higher sensitivity
diselenides and ditellurides, which could be manipulated with the and milder responsive condition. Hence, it is important to
presence or absence of visible light. Additionally, the apparent develop new DCBs with lower bond energies and metathesis
activation energy of the exchange process was measured to be only reactions with lower apparent activation energies.
28.01 kJ mol-1, explaining the high reactivity and sensitivity to light.
Besides, the low bond energy of diselenide bond also
28
contributes to their sensitive redox responsivity.27,
Some
Dynamic covalent bonds (DCBs), which can undergo reversible
formation, cleavage and metathesis under defined conditions,
have attracted increasing attention and have been widely used
in dynamic combinatorial chemistry (DCC) as well as
supramolecular chemistry.1-6 DCBs exhibit both reversibility and
stability compared with covalent or non-covalent interactions.
Therefore, in the last few decades, a series of DCBs, including
boronic ester bonds,7 imine bonds,8, 9 disulfide bonds,10 etc.,
enzymes play critical roles in physiological processes
accompanied by the transformation between different
selenium-containing DCBs. The selenoenzyme glutathione
peroxidase (GPx), for example, catalyzes the reduction of
hydroperoxides through the transformation between Se-Se and
Se-S bonds.29 Great efforts have been devoted to mimicking the
behaviour of such enzymes.30-34 But the essential question,
which is the conversion and regulation of selenium-containing
DCBs, is still not well understood. Therefore, it is of vital
importance to investigate and regulate the conversion of
different selenium-related DCBs, including the reaction
conditions, mechanism, apparent activation energy and so on.
Tellurium is one of the semi-metallic elements and is in group
XVI of the periodic table.35 Compared with other members of
the chalcogen family, tellurium has a larger atomic radius and
weaker electronegativity, which endow this element with
unique physical and chemical properties. In recent years, a
series of organic and inorganic tellurium compounds have been
prepared and applied as functional materials, such as
fluorescent molecular probes,36 responsive systems,37
superconductors,38 lithium batteries,39 thermoelectric
materials40, polymerization initiators41 and so on.42 The bond
energy of the ditelluride bond is only 126 kJ mol-1, which is much
lower than that of the disulfide bond (240 kJ mol-1).23 The lower
bond energy may result in milder cleavage conditions and
higher reactivity. Therefore, by taking advantage of this low
bond energy, the metathesis reaction between ditellurides and
diselenides may be induced by visible light, and a novel Se-Te
DCB can thus be realized.
12
have been extensively applied to self-healing materials,11,
stimuli-responsive systems,13-15 molecular machines16, 17 and so
on.18, 19
The stimuli-responsive conditions of dynamic functional
materials are closely related to the activity of DCBs. For
example, materials containing aliphatic disulfide bonds usually
undergo a stimuli-responsive process with the addition of
catalytic reductants or with the irradiation of ultraviolet (UV)
light.20-22 The harsh reaction conditions can be attributed to the
high bond energy (240 kJ mol-1) and apparent activation energy
(higher than 40 kJ mol-1), which result in slower kinetics for the
disulfide metathesis.23, 24 Compared with disulfide bonds, the
bond energy of diselenide is only 172 kJ mol-1.23 This decrease
in bond energy allows diselenides to exchange under milder
visible light.25 As a result, diselenide bonds containing
polyurethane elastomers have been proved to be self-healable
under visible light.26 It can be seen that DCB with lower bond
energy and metathesis reaction with lower apparent activation
a. Key Lab of Organic Optoelectronics and Molecular Engineering
Department of Chemistry, Tsinghua University
Herein, we present a novel selenium-related DCB, i.e., the Se-
Te bond, which was realized by a metathesis reaction between
diselenides and ditellurides (Scheme 1). Furthermore, we also
Beijing 100084, People’s Republic of China
E-mail: xuhuaping@mail.tsinghua.edu.cn
Electronic Supplementary Information (ESI) available: [details of any supplementary
information available should be included here]. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
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investigated in detail the initiating conditions, reaction applicable to various species of diselenide and ditelluride
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DOI: 10.1039/C9CC00252A
mechanism and apparent activation energy for the conversion reactants.
process from Se-Se to Se-Te. Four diselenides and two
ditelluride were utilized for the formation of Se-Te (Figure S1).
In this study, it was illustrated that the metathesis reaction
between diselenides and ditellurides can proceed under visible
light irradiation. This study further reveals the dynamic essence
of the selenium-related bond, enriches the selenium chemistry
knowledge base and may provide an alternative selenium-
containing DCB to prepare functional materials.
Scheme 1 A visible-light-responsive metathesis reaction proceeding through a radical
mechanism without catalysts.
1
First, H, 77Se and 125Te NMR spectra were employed to
confirm that the metathesis reaction occurred successfully
(Figure 1). The catalyst-free reaction was conducted under
irradiation from a white LED light with intensity of 118 Lux at
room temperature (20 °C) with diphenyl ditelluride ((PhTe)2)
and dibenzyl diselenide ((BenSe)2) at a concentration of 20 mM
of each reactant in dimethyl sulfoxide (DMSO) for 30 minutes.
The ratio of products (Se-Se, Se-Te, Te-Te) reached about 1:1:2
at equilibrium with the starting feed ratio of 1:1 between
diselenide and ditelluride. The equilibrium was controlled by
the difference in bond energy between Te-Te, Se-Te and Se-Te
analogues, but insensitive to the substitution on the diselenide
component (Figure S3). In the 1H NMR spectrum, there was only
one peak (peak a) corresponding to the CH2Se protons in
(BenSe)2 (Figure 1b). After the reaction, the peak a belonging to
Figure 1 a) Metathesis reaction between (PhTe)2 and (BenSe)2 (20 mM each, in DMSO).
1H b), 77Se c) and 125Te d) NMR spectra obtained before and after the exchange reaction.
After exchange reaction, the peak a belonging to Ha in (BenSe)2 at 3.90 ppm decreased
in intensity. And a new peak b belonging to Hb in exchange product (BenSe-TePh)
appeared at 4.33pm. The peak c belonging to Hc in (PhTe)2 at 7.80 ppm decreased in
intensity. And a new peak d belonging to Hd in BenSe-TePh appeared at 7.58 ppm. A new
peak f corresponding to the selenium atom in BenSe-TePh appeared at 231.89 ppm. A
new peak h corresponding to the tellurium atom in BenSe-TePh appeared at 707.43 ppm.
the CH2Se protons at 3.90 ppm decreased in intensity, and a
new peak b appeared at 4.33 ppm, indicating that some of the
CH2Se protons were in a new chemical environment. In the
aromatic region, it can be observed that the peak c at 7.80 ppm
for (PhTe)2 decreased in intensity, and a new peak d appeared
at 7.58 ppm after the reaction, which proved the feasibility of
the exchange reaction.
To further illustrate that such a metathesis reaction could
proceed successfully, we also used 77Se and 125Te NMR spectra
to provide more evidence. In the 77Se NMR spectra (Figure 1c),
the most obvious change before and after the reaction was the
appearance of a new peak f, which demonstrated that a new
chemical environment for the selenium element had emerged.
From the 125Te NMR spectra (Figure 1d), we also found that a
new peak h appeared after the reaction, which could be
attributed to a new chemical environment for the tellurium
element. These results confirmed the production of new
selenium- and tellurium- containing molecules after the
exchange reaction. In addition to (BenSe)2, the exchange
reaction between the other kinds of diselenides and ditellurides
was also confirmed by NMR spectra (Figures S4, S5 and S6).
These 1H, 77Se and 125Te NMR spectra indicated that a
metathesis reaction has indeed occurred and that it is widely
After ensuring that the reaction could successfully occur,
further insight into the role of light in this exchange reaction
was sought. First, it was found that not only visible light but also
light with a wavelength above 600 nm is sufficient to initiate the
reaction. The reaction between (HOC11Se)2 and (PhTe)2 (5 mM
each) reached equilibrium within 80 minutes when light below
600 nm was totally filtered out (Figure 2a, Figure S7), illustrating
the extreme sensitivity of the exchange reaction to light
stimulation. The equilibrium composition for reaction triggered
by red light was the same as that triggered by white LED light,
which also contained the Se-Se, Te-Te and Se-Te molecules with
the ratio of 1:1:2 (Figure S8). Second, once the reactants were
sheltered from light irradiation, the exchange process
immediately stopped. Before reaching equilibrium, the reaction
between (HOC11Se)2 and (PhTe)2 continuously proceeded
under visible-light irradiation. Once the light was turned off, the
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exchange process stopped immediately, and the reaction did in accordance with the signal of a tellurol radical adduct of
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not continue until the light irradiation was resumed (Figure 2b), DMPO (Figure S10). The g value was founDdOtoI: 1b0e.1023.09/0C695C8C,0w02h5ic2hA
which demonstrated the intensity dependence of the exchange corresponds to the value of a free electron (2.0023). In addition
reaction on light irradiation. The above experiments showed to the tellurol radical, we also captured the selenol radical in the
the excellent controllability of the exchange reaction, which same way (Figure 2d). Unlike the tellurol radical, a hyperfine
could be manipulated with the presence or absence of visible splitting effect was observed in the peak of the selenol radical
light at ambient temperature.
(Figure S10). The g value for the selenol radical was 2.00704.
Apart from (BenSe)2, the radical signal of several other kinds of
diselenides used in this study were also trapped in the same way
(Figure S11). It is worth noting that the intensity of signal varied
with the structure of the diselenide molecules, which
demonstrated different stabilities and reactivities of the selenol
radicals. Thus, both the evidence from the indirect methods and
EPR results indicate a radical mechanism. Additionally, as light
irradiation leads to the generation of radicals, the intensity
dependence of the metathesis reaction on light can be
explained.
The metathesis reaction could proceed in various solvents.
Apart from DMSO, it could also be conducted in chloroform,
acetone, acetonitrile and methanol, with the confirmation of 1H
NMR (Figure S12, S13, S14, S15). The spectra showed that the
reaction is independent on specific solvents and is compatible
with low-polarity, high-polarity and protic solvents. Moreover,
the dynamic exchange process could be influenced by oxygen,
which could be attributed to the low energy of ditelluride bond
and great activity of tellurol radicals. (Figure S16).
Figure 2 The dependence of the exchange reaction on light and EPR experiment for the
radical reaction mechanism. a) The metathesis reaction between (HOC11Se)2 and
(PhTe)2 (5 mM each, in DMSO) under light irradiation at a wavelength above 600 nm for
80 minutes. b) The exchange process could be turned on or off by the presence or
absence of visible light, respectively. The tellurol c) and selenol d) radical signals trapped
by the EPR technique.
Because of the convenience of monitoring reaction process
1
by H NMR, (BenSe)2 and (PhTe)2 (10 mM each) were used as
model molecules to determine the reaction order and apparent
activation energy. Aiming to establish the dependence of the
initial reaction rate on the concentration of each reactant, a
series of experiments with different initial concentrations were
conducted at 40 °C in DMSO without light irradiation. As shown
in Figure 3a and 3b, we found that the initial reaction rate
After recognizing the dependence of the exchange reaction
on light, the reaction mechanism was investigated. It has been
proven that diselenide metathesis can proceed through a
radical mechanism under the irradiation of visible light.25 The
importance of light together with the characteristics of the
diselenide bonds implies that the exchange reaction between
diselenide and ditelluride also proceeds through a radical
mechanism. First, the reaction could be activated only by
heating in the dark, which could be attributed to the heat
cleavage of the diselenide and ditelluride bonds. Second, the
metathesis process was significantly suppressed by the addition
of 2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO), which could
quench reactive radical intermediates during the exchange
process (Figure S9).
Electron paramagnetic resonance (EPR) is a useful tool to
confirm the presence of reactive radical intermediates. Aiming
to further verify the radical mechanism, we utilized EPR to
detect the tellurol and selenol radical signals with the spin
trapping agent 5,5-dimethyl-1-pyrroline N-oxide (DMPO)
(Figure S10). As shown in Figure 2c, for (PhTe)2, no radical signal
was observed in the dark. However, once visible light was
applied, an intense signal appeared immediately. The peak
shape was due to the cleavage effect of the nitrogen atom and
the β hydrogen atom on the free radical. The coupling and
splitting constants for the nitrogen and β hydrogen atoms were
Figure 3 Kinetics research for the exchange reaction. a) The initial reaction rate exhibited
first-order kinetics with respect to [(BenSe)2] with a fixed concentration of (PhTe)2 (10
mM). b) The initial reaction rate showed first-order kinetics with respect to [(PhTe)2]
with a fixed concentration of (BenSe)2 (10 mM). c) The linear dependence between lnk
and 1/T, where k is the reaction rate constant and the T is the temperature in Kelvins.
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10 A. Rekondo, R. Martin, A. Ruiz de Luzuriaga, G. Cabanero, H. J.
Grande and I. Odriozola, Mater. Horiz.D, 2O0I:1140,.110,3V92i/e3Cw79A-C2rtCi4c0l0e0.O2n5li2nAe
11 K. Imato, M. Nishihara, T. Kanehara, Y. Amamoto, A. Takahara
and H. Otsuka, Angew. Chem. Int. Ed., 2012, 51, 1138-1142.
12 H. Ying, Y. Zhang and J. Cheng, Nat. Commun., 2014, 5, 3218.
13 R. J. Wojtecki, M. A. Meador and S. J. Rowan, Nat. Mater.,
2011, 10, 14-27.
14 D. Roy, J. N. Cambre and B. S. Sumerlin, Prog. Polym. Sci.,
2010, 35, 278-301.
15 A. W. Jackson and D. A. Fulton, Polymer Chemistry, 2013, 4,
31-45.
exhibited first-order kinetics with respect to the concentration
of both (PhTe)2 and (BenSe)2. Then, the rate constants k at
different temperatures (40 °C, 50 °C, 60 °C, 70 °C and 80 °C)
were determined, and an apparent activation energy of 28.01
kJ mol-1 was calculated according to the Arrhenius equation, as
shown in Figure 3c. The apparent activation energy is lower
than that of the metathesis between diselenide analogues,
which is in accordance with the higher activity. Therefore, this
metathesis reaction may provide an alternative method for
rapid exchanges within dynamic covalent materials.
16 M. von Delius, E. M. Geertsema and D. A. Leigh, Nat. Chem.,
2010, 2, 96-101.
In conclusion, by taking advantage of low bond energy of
ditelluride, a metathesis reaction between diselenides and
ditellurides was successfully realized. The reaction could be
induced by visible light without catalysts. Furthermore, the
exchange process could be controlled by the presence or
absence of visible light irradiation. The features of high
reactivity and light dependence were further revealed by a low
apparent activation energy and a free radical mechanism.
Additionally, a novel Se-Te bond was obtained from the
exchange process, which should be a new DCB that will further
enrich the knowledge base of selenium-related dynamic
chemistry. With the development of selenium-related
chemistry, it is believed that an increasing number of
applications, such as self-adaptive chemistry, dynamic
functional materials,43 selenoenzyme mimics and surface
modification44 will be discovered based on the metathesis
reaction between diselenides and ditellurides.
This work was financially supported by National Natural
Science Foundation of China (Grant numbers 21734006,
91427301), the National Science Foundation for Distinguished
Young Scholars (Grant 21425416) and the Foundation for
Innovative Research Groups of the National Natural Science
Foundation of China (21821001). We are grateful to Prof.
Yuqing Wu, Prof. Ming-Tian Zhang, Prof. Jianping Zhang and Mr
Fuqiang Fan for their helpful discussions.
17 M. J. Barrell, A. G. Campana, M. von Delius, E. M. Geertsema
and D. A. Leigh, Angew. Chem. Int. Ed., 2011, 50, 285-290.
18 W. Zou, J. Dong, Y. Luo, Q. Zhao and T. Xie, Adv. Mater., 2017,
29, 1606100.
19 M. Chen, Y. Gu, A. Singh, M. Zhong, A. M. Jordan, S. Biswas, L.
T. J. Korley, A. C. Balazs and J. A. Johnson, ACS Cent. Sci., 2017,
3, 124-134.
20 M. Arisawa and M. Yamaguchi, J. Am. Chem. Soc., 2003, 125,
6624-6625.
21 R. Caraballo, M. Rahm, P. Vongvilai, T. Brinck and O.
Ramstrom, Chem. Commun., 2008, 6603-6605.
22 H. Otsuka, S. Nagano, Y. Kobashi, T. Maeda and A. Takahara,
Chem. Commun., 2010, 46, 1150-1152.
23 N. K. Kildahl, J. Chem. Educ., 1995, 72, 423-424.
24 A. Fava, A. Iliceto and E. Camera, J. Am. Chem. Soc., 1957, 79,
833-838.
25 S. Ji, W. Cao, Y. Yu and H. Xu, Angew. Chem. Int. Ed., 2014, 53,
6781-6785.
26 S. Ji, W. Cao, Y. Yu and H. Xu, Adv. Mater., 2015, 27, 7740-
7745.
27 N. Ma, Y. Li, H. Xu, Z. Wang and X. Zhang, J. Am. Chem. Soc.,
2010, 132, 442-443.
28 C. Sun, S. Ji, F. Li and H. Xu, ACS Appl. Mater. Interfaces, 2017,
9, 12924-12929.
29 J. T. Rotruck, A. L. Pope, H. E. Ganther, A. B. Swanson, D. G.
Hafeman and W. G. Hoekstra, Science, 1973, 179, 588-590.
30 X. Zhang, H. P. Xu, Z. Y. Dong, Y. P. Wang, J. Q. Liu and J. C.
Shen, J. Am. Chem. Soc., 2004, 126, 10556-10557.
31 G. Mugesh and H. B. Singh, Chem. Soc. Rev., 2000, 29, 347-
357.
32 K. P. Bhabak and G. Mugesh, Acc. Chem. Res., 2010, 43, 1408-
1419.
33 X. Huang, X. Liu, Q. Luo, J. Liu and J. Shen, Chem. Soc. Rev.,
2011, 40, 1171-1184.
Conflicts of interest
There are no conflicts to declare.
34 H. Xu, W. Cao and X. Zhang, Acc. Chem. Res., 2013, 46, 1647-
1658.
35 J. Ibers, Nat. Chem., 2009, 1, 508-508.
36 S. T. Manjare, Y. Kim and D. G. Churchill, Acc. Chem. Res.,
2014, 47, 2985-2998.
37 W. Cao, Y. Gu, M. Meineck, T. Li and H. Xu, J. Am. Chem. Soc.,
2014, 136, 5132-5137.
38 X. Zhong, H. Wang, J. Zhang, H. Liu, S. Zhang, H.-F. Song, G.
Yang, L. Zhang and Y. Ma, Phys. Rev. Lett., 2016, 116, 057002.
39 Y. Liu, J. Wang, Y. Xu, Y. Zhu, D. Bigio and C. Wang, J. Mater.
Chem. A, 2014, 2, 12201-12207.
40 S. Lin, W. Li, Z. Chen, J. Shen, B. Ge and Y. Pei, Nat. Commun.,
2016, 7, 10287.
41 Y. Nakamura, B. Ebeling, A. Wolpers, V. Monteil, F. D'Agosto
and S. Yamago, Angew. Chem. Int. Ed., 2018, 57, 305-309.
Notes and references
1
2
J. M. Lehn, Chem. Eur. J., 1999, 5, 2455-2463.
S. J. Rowan, S. J. Cantrill, G. R. L. Cousins, J. K. M. Sanders and
J. F. Stoddart, Angew. Chem. Int. Ed., 2002, 41, 898-952.
Y. Jin, C. Yu, R. J. Denman and W. Zhang, Chem. Soc. Rev.,
2013, 42, 6634-6654.
3
4
5
A. Herrmann, Chem. Soc. Rev., 2014, 43, 1899-1933.
R. Cacciapaglia, S. D. Stefano and L. Mandolini, J. Am. Chem.
Soc., 2005, 127, 13666-13671.
6
7
8
9
M. Ciaccia, I. Tosi, L. Baldini, R. Cacciapaglia, L. Mandolini, S.
D. Stefano and C. A. Hunter, Chem. Sci., 2015, 6, 144-151.
O. R. Cromwell, J. Chung and Z. Guan, J. Am. Chem. Soc., 2015, 42 Y. S. Park, T. S. Kale, C. Y. Nam, D. Choi and R. B. Grubbs, Chem.
137, 6492-6495.
M. E. Belowich and J. F. Stoddart, Chem. Soc. Rev., 2012, 41, 43 F. Q. Fan, S. B. Ji, C. X. Sun, C. Liu, Y. Yu, Y. Fu and H. P. Xu,
2003-2024.
Angew. Chem. Int. Ed., 2018, 57, 16426-16430.
M. Ciaccia and S. D. Stefano, Org. Biomol. Chem., 2015, 13, 44 J. H. Xia, P. Zhao, K. Zheng, C. J. Lu, S. C. Yin and H. P. Xu,
646-654.
Angew. Chem. Int. Ed., 2018, 58, 542-546.
Commun., 2014, 50, 7964-7967.
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