Metal ions-triggered photo-induced fluorescence change in rhodamine B-based photo-responsive complexes

Article abstract of DOI:10.1016/j.saa.2020.118069

Photo-responsive materials with tunable properties by multiple stimuli have been widely used as molecular machines, molecular logic gates, optical data storages, etc. In this work, we report a rhodamine B-based photo-responsive system, whose properties co

Full text of DOI:10.1016/j.saa.2020.118069

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Metal ions-triggered photo-induced fluorescence change in
rhodamine B-based photo-responsive complexes
Yuanyuan Li, Zining Feng, Yajing Li, Wenhui Jin, Qiuchen Peng,
Panke Zhang, Juan He, Kai Li
PII:
S1386-1425(20)30046-9
https://doi.org/10.1016/j.saa.2020.118069
SAA 118069
DOI:
Reference:
Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy
To appear in:
Received date: 5 October 2019
Revised date:
9 January 2020
11 January 2020
Accepted
date:
Please cite this article as: Y. Li, Z. Feng, Y. Li, et al., Metal ions-triggered photo-induced
fluorescence change in rhodamine B-based photo-responsive complexes, Spectrochimica
Acta Part A: Molecular and Biomolecular Spectroscopy(2018), https://doi.org/10.1016/
j.saa.2020.118069
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Metal ions-triggered photo-induced fluorescence change in rhodamine B-based
photo-responsive complexes
a
a
a
a
b
Yuanyuan Li , Zining Feng , Yajing Li , Wenhui Jin , Qiuchen Peng , Panke Zhang b,*
,
Juan He a, Kai Li b,*
aSchool of Chemistry and Chemical Engineering, Henan University of Technology, Henan
450001, P. R. China.
bCollege of Chemistry and Molecular Engineering, Zhengzhou University, Henan 450001, P.
R. China. E-mail: likai@zzu.edu.cn.
Abstract
Photo-responsive materials with tunable properties by multiple stimuli have been
widely used as molecular machines, molecular logic gates, optical data storages, etc.
In this work, we report a rhodamine B-based photo-responsive system, whose
properties could be facilely modulated by metal ions (Zn(II), Ni(II) and Hg(II)). These
metal ions endow the complexes (L-Zn, L-Ni and L-Hg) with similar photochromic
property but distinctly different photo-induced fluorescence change. Upon UV light
irradiation, the spirolactam ring in rhodamine B moiety turned from a close form to an
open form, along with enlarged conjugated structure with intense absorbance.
Interestingly, fluorescence “turn off”, “no change” and “turn on” responses were
induced by Zn(II), Ni(II) and Hg(II) respectively upon UV light irradiation. Taking
advantage of the prominently different characteristics caused by metal ions, different
logic gates were designed by simply varying the inputs of metal ions and UV light.
This work provided a new strategy for developing multifunctional photo-responsive
materials, which were further beneficial for constructing photo-controlled logic gates
with tunable performance.
Keywords: Photo-responsive; Rhodamine B; Metal ion; Fluorescence change; Logic
gate
1. Introduction
Photo-responsive materials are a kind of materials which can undergo physical or
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chemical transformations under light stimulation [1, 2]. Because of the
light-controlled properties, photo-responsive materials have attracted wide attentions
in constructing a variety of functional materials including molecular machines,
molecular logic gates, optical data storages, fluorescence sensors, photo-controllable
switches, etc [3-13]. Some multifunctional photo-responsive systems including
azobenzene, spiropyran, spirooxazine, dithienylethene, viologen and anil are reported
successively [14-19].
In recent years, great efforts have been made on combining various stimuli with
light to endow photo-responsive materials with more abundant properties, which have
become a hot topic for developing multifunctional photo-responsive materials. Up to
now, the stimuli including pH, heat, electricity and mechanical force have been
introduced to the development of multifunctional photo-responsive materials [20-27].
Metal ions, however, to the best of our knowledge, have been rarely reported as a kind
of efficient stimulus in regulating photo-responsive performance. It is still a great
challenge to develop metal-controlled photo-responsive systems with tunable
performances.
Rhodamine B salicylaldehyde hydrazone metal complex, a more recently
reported photo-responsive system, has the advantages of simple synthesis, distinct
color change upon UV light irradiation, and good fatigue resistance [28-32].
Meanwhile, its metal complex structure makes it a good candidate and possible to
regulate the photo-responsive property by metal ions. Therefore, in this work,
2,4-dihydroxybenzaldehyde rhodamine B hydrazone Schiff base (L) was chosen as
ligand and attempts have been made to systematically regulate the photo-responsive
performance by changing the types of metal ions (Table 1). Although the complexes
(L-M) formed by L and metal ions (M) exhibited similar isomerization in the
spirolactam ring of rhodamine B moiety from a close form to an open form, they
showed different photo-responsive properties upon UV light irradiation. Zn(II) can
induced the absorbance change from nothing to an obvious value at 556 nm with a
quenched fluorescence emission at 516 nm after UV light irradiation. Ni(II) caused
similar absorbance change to that of Zn(II) after UV light irradiation but no
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fluorescence was observed whether or not the complex was irradiated. For Hg(II),
however, the properties were rather different. Both of the absorbance (556 nm) and
fluorescence (589 nm) were significantly enhanced after UV light irradiation. Taking
advantage of the prominently different characteristics caused by metal ions, different
logic gates were facilely designed by simply varying the inputs of metal ions and UV
light.
Table 1. Fluorescence and absorption properties of L regulated by Zn(II), Ni(II) and Hg(II)
before and after UV light irradiation.
Irradiation
Before
After
L-Zn
Strong
Weak
No
L-Ni
No
L-Hg
Weak
Strong
Weak
Strong
Fluorescence
Absorbance
No
Before
After
No
Strong
Strong
2. Experimental
2.1. Materials
All the materials of analytical grade were used from the suppliers without further
purification. Rhodamine B, benzoyl hydrazine, hydrazine hydrate and
2,4-dihydroxybenzaldehyde were ordered from J&K Chemical Co., Beijing, China.
Zinc(II) nitrate hexahydrate, nickel(II) nitrate hexahydrate and mercury(II)
perchlorate hydrate were purchased from Energy Chemical Co., Shanghai, China. All
the other materials were supplied by Sinopharm Chemical Reagent Beijing Co.,
Beijing, China.
2.2. Apparatus
Fluorescence spectra were recorded on a JASCO FP-8300 spectrofluorimeter (1
cm quartz cell). Absorption spectra were determined on a JASCO V-750
spectrophotometer (0.2 cm quartz cells for L-Zn and L-Ni and 1 cm quartz cells for
L-Hg). Electrospray ion mass spectrometry (ESI-MS) data were collected on an
Agilent Technologies 6420 triple quadrupole LC/MS spectrometer without using the
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LC part. The nuclear magnetic resonance (NMR) spectra were collected on a Bruker
600 Avance NMR spectrometer. UV light of 365 nm was produced by a Qiwei
WFH-204B hand-held ultraviolet lamp. All the photos were carried by a Nikon D5500
camera.
2.3. Syntheses
Syntheses of L: The synthetic route for L was shown in Scheme 1 [33].
Rhodamine B hydrazide was prepared with rhodamine B (8 mmol, 3.54 g) and
hydrazine hydrate (85%) by refluxing in 30 mL ethanol for 6 h [34]. Then rhodamine
B hydrazide (4 mmol, 1.83 g) was dissolved in 60 mL absolute ethanol. After that
2,4-dihydroxybenzaldehyde (5 mmol, 0.69 g) was added dropwise with vigorous
stirring. The mixture was heat to 80 oC and refluxed overnight. After that, the solvent
was concentrated to about 15 mL under reduced pressure, followed by standing at 4
oC overnight to form a pink precipitate. After being filtered, the precipitate was
washed with 50 mL absolute ethanol for three times. The resulting precipitate was
1
finally dried under reduced pressure to yield a pink solid (1.50 g, yield 65%). H
NMR (600 MHz, DMSO-d6) δ (ppm): 10.54 (s, 1H), 9.02 (s, 1H), 7.89 (s, 1H), 7.56
(m, 2H), 7.09 (s, 1H), 6.35 (m, 8H), 6.18 (s, 1H), 3.30 (q, 8H), 1.07 (t, 12H). 13C
NMR (151 MHz, DMSO-d6) δ (ppm): 163.60, 161.61, 159.95, 153.24, 152.97, 151.35,
148.99, 134.12, 132.19, 129.51, 129.28, 128.19, 124.27, 123.35, 111.02, 108.63,
108.34, 105.41, 103.09, 97.81, 65.94, 44.13, 12.87.
Syntheses of 2,4-dihydroxybenzaldehyde benzoyl hydrazine Schiff base (L1):
Benzoyl hydrazine (4 mmol, 0.54 g) and 2,4-dihydroxybenzaldehyde (4 mmol, 0.55 g)
were dissolved in 60 mL absolute ethanol. The mixture was heat to 80 oC and refluxed
for 30 min. After that, the solvent was cooled to room temperature and then filtered.
Precipitate was collected and washed with 50 mL absolute ethanol for three times.
After drying under reduced pressure, a pink solid (0.83 g, yield 81%) was obtained.
1H NMR (600 MHz, DMSO-d6) δ (ppm): 11.96 (s, 1H), 8.54 (s, 1H), 7.95 (d, 2H),
7.60 (t, 1H), 7.54 (t, 2H), 7.32 (d, 2H), 6.39 (m, 2H). 13C NMR (151 MHz, DMSO-d6)
δ (ppm): 163.01, 161.27, 160.04, 149.77, 133.49, 132.26, 131.87, 128.97, 128.03,
110.99, 108.20, 103.19.
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Scheme 1. Synthetic route of L and L1.
2.4. Preparation of the complexes of L-Zn, L-Ni and L-Hg
Stock solutions of Zn(II), Ni(II) and Hg(II) were prepared from their nitrate salts
or perchlorate salts of analytical grade in doubly distilled deionized water. Stock
solution of L was prepared in tetrahydrofuran. Solutions of L-Zn, L-Ni and L-Hg
were prepared by adding 10 equiv. of the corresponding metal salts separately to the
solution of L to ensure L can convert to complexes adequately.
3. Results and discussion
3.1. The bonding mode of L with metal ions
To get insight into the bonding mode of different metal ions with L, UV-vis
titration experiments were carried out. As shown in Fig. 1, all of the metal ions of
Zn(II), Ni(II) and Hg(II) can cause increased absorbance of L in visible region. The
absorption bands centered at around 410 nm, 421 nm and 558 nm, respectively.
Isosbestic points were observed in all the spectra after the titration experiments, which
suggested that new compounds have been formed between the ligand and Zn(II), Ni(II)
and Hg(II) (L-Zn, L-Ni and L-Hg). Moreover, the metal-to-ligand ratios could be
obtained from the absorbance titration data of the metal ions and L based on the
following equation [35, 36]:
퐴−퐴
0
[ ]
log (퐴 −퐴) = log 퐾 + 푛 log M (1)
푚푎푥
where A is the absorbance of ligand as a function of the addition of metal ions,
A0 represents the absorbance of ligand without metal ions and Amax is the absorbance
of ligand with excess amount of metal ions. K represents the association constant and
n is the stoichiometry of the complex between ligand and metal ions, respectively. [M]
stands for the concentrations of metal ions. As shown in the insets of Fig. 1(b), Fig.
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1(d) and Fig. 1(f), excellent linear relationships could be obtained between
log[(A-A0)/(Amax-A)] and log[M] (R2 = 0.989, 0.995 and 0.988). The slopes of n were
0.959 for L with Zn(II) and 0.995 for L with Ni(II), which were both approximately
equal to 1, suggesting that 1:1 metal-to-ligand complexes were formed between L and
Zn(II) (or Ni(II)). Unlike these two ions, the slope of n for L and Hg(II) was 2.022,
which was close to 2, revealing the stoichiometric ratio of 2:1 between L and Hg(II).
On the other hand, the association constant K could be also obtained as 9.183×103
L/mol, 2.818×104 L/mol and 4.797×109 L2/mol2 for Zn(II), Ni(II) and Hg(II) with L,
respectively.
Fig. 1. Absorption spectra of L upon the addition of (a) Zn(II), (c) Ni(II) and (e) Hg(II) in
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tetrahydrofuran. Absorbance at 410 nm, 421 nm and 558 nm as a function of the
concentrations of (b) Zn(II), (d) Ni(II) and (f) Hg(II), respectively. Inset: linear fitting
between log[(A-A0)/(Amax-A)] and log[M].
Another direct evidence for the stoichiometric ratio between L and the metal ions
were derived from ESI-MS spectra. There were peaks at m/z = 639.22, 633.23 and
1353.52, respectively for L-Zn, L-Ni and L-Hg, which corresponded well with the
calculated ones ([L + Zn(II) - H]+, calcd 639.20, [L + Ni(II) - H]+, calcd 633.20 and
[2L + Hg(II) - H]+, calcd 1353.51). All of the results verified that the stoichiometric
ratios of L with Zn(II) and Ni(II) were both 1:1 while that of L with Hg(II) was 2:1.
3.2. Photo-induced absorbance and fluorescence change of L with different metal
ions
The influences of metal ions on the photo-responsive behavior of L were first
evaluated by absorption measurements of L-M before and after UV light irradiation.
As shown in Fig. 2, both L-Zn and L-Ni showed no absorbance above 470 nm before
UV light irradiation. Whereas the unirradiated L-Hg exhibited a weak absorbance
band at about 556 nm. Interestingly, after UV light irradiation, intense absorbance
peaks were induced by Zn(II) and Ni(II) around 556 nm. Meanwhile, the peak
observed in the unirradiated L-Hg was enhanced remarkably. These absorbance
changes corresponded well with the color changes observed from the photographs in
Fig. 2. Before UV light irradiation, L-Zn was nearly colorless while L-Ni showed
faint yellow color, which was due to the absorbance bellow 470 nm. L-Hg was pink
originated from its absorbance at 556 nm. After exposure to UV light, these three
complexes were all getting to deepred, which were attributed to their dominant
absorbance at about 556 nm. The increased absorbance of L-Zn, L-Ni and L-Hg can
gradually return to their originated states when the UV light was removed, which
demonstrated that the photo-responsive behaviors of L-M were all reversible.
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Fig. 2. Absorption spectra and photographs of L with (a) Zn(II), (b) Ni(II) and (c) Hg(II)
before and after UV light irradiation.
Fluorescence measurements of L with Zn(II), Ni(II) and Hg(II) before and after
UV light irradiation were further carried out. Interestingly, these three complexes
showed totally different variation tendency. As shown in the fluorescence photographs
(Fig. 3 inset), L-Zn emitted strong green emission and L-Hg showed a very weak
orange emission before UV light irradiation, respectively. On the contrary, L-Ni was
almost nonluminous before UV light irradiation. After exposure to UV light, the
emission of L-Zn was quenched while that of L-Hg enhanced. On the other hand,
there was still no emission observed for L-Ni. To deeply investigate the fluorescence
changes, their fluorescence spectra were recorded with different irradiation time. As
shown in Fig. 3, there was an intense emission peak at 516 nm for unirradiated L-Zn.
This peak split into two peaks with decreased intensities upon UV light irradiation
(“turn off” mode). For L-Hg, the weak emission peak at 589 nm enhanced gradually
with UV light irradiation time (“turn on” mode). While for L-Ni, no fluorescence
peak can be observed regardless of whether there was UV light irradiation. As shown
in Table S1, the luminescence quantum yield of L-Zn decreased while that of L-Hg
increased after UV light irradiation, which were in accord with the variation trends of
fluorescence intensities.
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Fig. 3. Fluorescence spectra and photographs of L with (a) Zn(II), (b) Ni(II) and (c) Hg(II)
before and after UV light irradiation.
According to reported literatures [31], the increased absorbance of L with Zn(II),
Ni(II) and Hg(II) could be originated from the isomerization of the complexes
(Scheme 2, take L-Zn as an example). After UV light irradiation, the spirolactam ring
in rhodamine B moiety turned from a close form (L-Zn-Close) to an open form
(L-Zn-Open), along with enlarged conjugated structure with intense absorbance
(Scheme 2, highlighted in red).
Scheme 2. Proposed mechanism for the isomerization of L-Zn upon UV light irradiation.
In order to understand the effects of metal ions on the distinctly different
fluorescence response of L-M upon UV light irradiation, a control compound L1 was
prepared (Scheme 1). Stoichiometric ratios between metal ions and L1 were
determined by UV-vis titration experiments (Fig. S1-S3), which showed the same
ratios to that between L and metal ions, i.e., 1:1 for L1-Zn and L1-Ni while 2:1 for
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L1-Hg. In the meantime, rhodamine B with ring-open form modulated by pH was
also studied. As shown in Fig. 4(a), the fluorescence emission of L-Zn was similar to
that of L1-Zn before UV light irradiation, suggesting the fluorescence of L-Zn was
originated from the blue part showed in Scheme 2. This intense fluorescence of L-Zn
can be attributed to the blocking effect on the photo-induced electron transfer (PET)
process induced by the coordination of Zn2+ with nitrogen atom [37, 38]. After UV
light irradiation, a valley at about 556 nm was observed in the same place of
absorbance band from the UV light irradiated L-Zn, which was also the same
absorbance peak position of rhodamine B with ring-open form (Fig. 4(b)). Meanwhile,
a small valley was found at L-Zn around 511 nm, which was also at the
unconspicuous absorbance peak position of rhodamine B. Thus, it can be determined
that the quenched emission of L-Zn was originated from the intense self-absorption of
the conjugated rhodamine B moiety. For L-Ni, there was no fluorescence whether or
not it was irradiated because Ni(II) was paramagnetic, which always has a quenching
effect on the fluorescence emission. For L-Hg, weak fluorescence emission at 589 nm
can be observed before UV light irradiation because of the strong polarization of
Hg(II), which can induce a ring open in spirolactam part. Thus, the weak fluorescence
before UV light irradiation was in fact coming from that of the rhodamine B part with
ring-open form (Fig. S4). After irradiated by UV light, more molecules of ring-open
form were generated, resulting in a turn on fluorescence emission.
Furthermore, the fluorescence lifetimes of the complexes before and after UV
light irradiation are investigated. As shown in Table S1, the fluorescence lifetimes of
L-Zn at 516 nm before and after UV light irradiation were similar (3.64 ns and 3.65
ns, respectively), suggesting that they were originated from the same part of 1-Zn. On
the contrast, the lifetime of UV light irradiated 1-Zn at 585 nm (2.26 ns) was different
from that at 516 nm (3.65 ns), which suggested that the emission of UV irradiated
1-Zn at 585 nm might came from another part, i.e., the rhodamine B part. The
lifetimes of L-Hg before and after UV light irradiation were 2.44 ns and 2.02 ns,
respectively, which were both close to that of L-Zn after UV light irradiation (2.26
ns), demonstrating these emissions were also belongs to the rhodamine B part.
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Fig. 4. (a) Fluorescence spectra of L-Zn and L1-Zn before UV light irradiation. (b)
Fluorescence spectrum of L-Zn after UV light irradiation and absorption spectrum of
rhodamine B with ring-open form.
3.3. The reversibility and fatigue resistance of L-M complexes
Besides the absorbance and fluorescence properties, the thermal bleaching
kinetics of the three complexes recovered from the L-M-Open form to L-M-Close
form can also be modulated by metal ions. Time dependent absorbance at 556 nm of
UV light irradiated L-M complexes in dark was shown in Fig. 5. As shown, the
recovery time of L-Zn, L-Ni and L-Hg was quite different, suggesting different
stability of the UV light irradiated L-M complexes. More importantly, all of the decay
curves showed excellent liner relationships between lnA and the recovery time (t)
according to the following equation [39]:
lnA = - kt
(2)
where A is the absorbance and k represents the bleaching rate constant. This liner
relationship demonstrated that the recovery from L-M-Open form to L-M-Close
form was a first order reaction. Meanwhile, k and half-life (t1/2) of the three
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complexes could be obtained as listed in Table S2.
Fig. 5. Thermal bleaching kinetics of L with Zn(II), Ni(II) and Hg(II). Inset: The curves of
lnA with time.
Fig. 6. Fatigue resistance of (a) L-Zn, (b) L-Ni and (c) L-Hg upon UV light irradiation and
standing in dark alternately.
As reversible photo-responsive systems, the fatigue resistances of the complexes
were investigated. L-Zn, L-Ni and L-Hg were toggled repeatedly between their
L-M-Open form and L-M-Close form for 10 times. As shown in Fig. 6, the
maximum absorbance at 556 nm of each complex stayed almost constant without
apparent degradation even after repetition for 10 times. These results demonstrated
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that all the three complexes have good fatigue resistance and excellent reversible
photo-responsive properties.
3.4. Construction of logic gates
Inspired by the tunable fluorescence and absorbance properties of L by metal
ions upon UV light, three logic gates could be constructed based on each individual
metal ion. With respect to the inputs, the presence of Zn(II), Ni(II) or Hg(II) (In1) as
well as the application of UV light irradiation (In2) were defined as “1” while their
absence was “0”. The fluorescence intensity and absorbance acted as the outputs of
O1 and O2, respectively. The output signals based on the fluorescence and absorbance
emissions and the constructed logic gates as well as their corresponding truth tables
were shown in Fig. 7. For L with Zn(II), fluorescence intensity at 516 nm was
considered due to the turn off emission of L-Zn upon UV light irradiation, where the
intensity of unirradiated L-Zn was chosen as “1” and that less than half of the
originated one (the turn-off emission) was defined as “0” (Fig. 7(a)). For the output of
O2, the absorbance at 556 nm was set as “1” while the absent absorbance was the “0”
signal (Fig. 7(d)). As shown in Fig. 7(d) inset and Fig. 7(g), only the input with Zn(II)
(In1 = 1, In2 = 0) can induce a fluorescence output signal (O1 = 1) while both the
presence of Zn(II) and UV light (In1 = 1, In2 = 1) resulted in a colored state with an
intense absorbance (O2 = 1). For Ni(II) with L, the insensitive fluorescence changes
suggested that its O1 channel could be always considered as “0” (Fig. 7(b)).
Nevertheless, its output of O2 with an absorbance band at 556 nm was set as “1”
otherwise it was the “0” signal (Fig. 7(e)). Therefore, a logic gate with the coexistence
inputs of Ni(II) and UV light (In1 = 1, In2 = 1) can induce an enhanced absorbance
(O2 = 1) but other output channels were all “0”. The cases of Hg(II) with L were
much different from the above two. On the one hand, the turn-on fluorescence
intensity at 589 nm after irradiated by UV light was taken into account as its output
channel of O1, with the fluorescence intensity of unirradiated L-Hg acting as “0” and
the turn on emission as “1” (Fig. 7(c)). On the other hand, the absorbance at 556 nm
was set as “1” (Fig. 7(f)). Therefore, the presence of both Hg(II) and UV light (In1 =
1, In2 = 1) resulted in the outputs of O1 = 1 and O2 = 1. The sole input of Hg(II) (ln1
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= 1, In2=0) can also bring an output of O2 = 1 due to its distinct absorbance with UV
light irradiation. Notably, different outputs of L could be facilely achieved by varying
the metal ions coupled with UV light, which provided a simple strategy for
developing photo-controlled logic gates with tunable performance.
Fig. 7. Bar diagrams of (a)-(c) fluorescence and (d)-(f) absorbance changes upon different
united inputs of metal ions and UV light irradiation. Inset: Schematic diagrams of the logic
gates with different inputs. (h)-(j) The corresponding truth tables of the logic gates based on
the metal ions and UV light irradiation ((a) (d) and (g) for Zn(II), (b) (e) and (h) for Ni(II), (c)
(f) and (i) for Hg(II)).
Conclusions
In conclusion, 2,4-dihydroxybenzaldehyde rhodamine B hydrazone Schiff base
of L was prepared in this work, whose absorption and fluorescence properties as well
as the thermal bleaching rate were efficiently modulated by metal ions. Stoichiometric
ratios between L and the metal ions of Zn(II), Ni(II) and Hg(II) were 1:1, 1:1 and 2:1,
respectively. Although the complexes L-M exhibited similar isomerization in the
rhodamine B moiety from their close form to open form with enhanced absorbance,
they showed entirely different photo-induced fluorescence properties upon UV light
irradiation. Especially, Zn(II) induced the fluorescence of L from an intense emission
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to two divisive quenched emissions while Hg(II) caused its fluorescence intensity
from weak to pronouncedly strong after the complexes were irradiated by UV light.
On the other hand, Ni(II) can not bring any fluorescence difference regardless of
whether L-Ni was irradiated by UV light or not. Taking advantage of the prominently
different characteristics caused by metal ions, different logic gates were facilely
designed by simply varying the inputs of metal ions and UV light. This work provided
a new strategy for developing multifunctional photo-responsive materials, which were
further beneficial for constructing photo-controlled logic gates with tunable
performance.
Acknowledgements
This research was supported by the foundations from National Natural Science
Foundation of China (U1904172, 51502079, 21501150 and 21575034), the Training
Program for Young Backbone Teachers of Henan University of Technology, the
Science and Technology Key Project of Henan Education Department (18A150026),
and the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous
Metals and Featured Materials, Guangxi University (2019GXYSOF12).
References
[1] D.-H. Qu, Q.-C. Wang, Q.-W. Zhang, X. Ma, H. Tian, Photoresponsive
host-guest functional systems, Chem. Rev. 115 (2015) 7543-7588.
[2] A. Fihey, A. Perrier, W.R. Browne, D. Jacquemin, Multiphotochromic
molecular systems, Chem. Soc. Rev. 44 (2015) 3719-3759.
[3] Y. Li, Q. Peng, S. Li, C. Yang, J. He, Q. Hu, K. Li, Facile synthesis of a
photoresponsive AIEgen used for monitoring UV light and photo-patterning,
Dyes Pigments 171 (2019) 107750.
[4] Y. He, Y. Li, H. Su, Y. Si, Y. Liu, Q. Peng, J. He, H. Hou, K. Li, An
o-phthalimide-based multistimuli-responsive aggregation-induced emission
(AIE) system, Mater. Chem. Front. 3 (2019) 50-56.
15

Journal Pre-proof
[5] K. Xu, B. Yu, Y. Li, H. Su, B. Wang, K. Sun, Y. Liu, Q. Peng, H. Hou, K.
Li, Photo-induced free radical production in a tetraphenylethylene ligand-based
metal-organic framework, Chem. Commun. 54 (2018) 12942-12945.
[6] L. Wang, Q. Li, Photochromism into nanosystems: towards lighting up the
future nanoworld, Chem. Soc. Rev. 47 (2018) 1044-1097.
[7] Y. Liang, R. Wang, G. Liu, S. Pu, Effects of heteroaryl ring on the
photochromism of asymmetrical diarylethenes containing a naphthalene group,
Spectrochim. Acta. A. 205 (2018) 470-478.
[8] L. Dong, Y. Feng, L. Wang, W. Feng, Azobenzene-based solar thermal
fuels: design, properties, and applications, Chem. Soc. Rev. 47 (2018)
7339-7368.
[9] R. Wang, X. Zhang, S. Pu, G. Liu, Y. Dai, Substituent effect in the
photochromism of two isomeric asymmetric diarylethenes having pyrrole and
thiophene units, Spectrochim. Acta. A. 173 (2017) 257-263.
[10] Q. Qi, C. Li, X. Liu, S. Jiang, Z. Xu, R. Lee, M. Zhu, B. Xu, W. Tian,
Solid-state photoinduced luminescence switch for advanced anticounterfeiting
and super-resolution imaging applications, J. Am. Chem. Soc. 139 (2017)
16036-16039.
[11] Z. Liu, H.I. Wang, A. Narita, Q. Chen, Z. Mics, D. Turchinovich, M.
Kläui, M. Bonn, K. Müllen, Photoswitchable micro-supercapacitor based on a
diarylethene-graphene composite film, J. Am. Chem. Soc. 139 (2017)
9443-9446.
[12] L. Wang, Y. Li, X. You, K. Xu, Q. Feng, J. Wang, Y. Liu, K. Li, H. Hou,
An erasable photo-patterning material based on a specially designed
4-(1,2,2-triphenylvinyl)aniline salicylaldehyde hydrazone aggregation-induced
emission (AIE) molecule, J. Mater. Chem. C 5 (2016) 65-72.
[13] M. Irie, T. Fukaminato, K. Matsuda, S. Kobatake, Photochromism of
diarylethene molecules and crystals: Memories, switches, and actuators, Chem.
Rev. 114 (2014) 12174-12277.
16

Journal Pre-proof
[14] M. Kathan, P. Kovaříček, C. Jurissek, A. Senf, A. Dallmann, A. F.
Thünemann, S. Hecht, Control of imine exchange kinetics with photoswitches
to modulate self-healing in polysiloxane networks by light illumination, Angew.
Chem. Int. Ed. 55 (2016) 13882-13886.
[15] J. Zhang, Q. Zou, H. Tian, Photochromic materials: more than meets the
eye, Adv. Mater., 25 (2013) 378-399.
[16] A. S. Lubbe, W. Szymanski, B. L. Feringa, Recent developments in
reversible photoregulation of oligonucleotide structure and function, Chem. Soc.
Rev., 46 (2017) 1052-1079.
[17] H. Qian, Y. Y. Wang, D. S. Guo, I. Aprahamian, Controlling the
Isomerization Rate of an Azo-BF2 Switch Using Aggregation, J. Am. Chem.
Soc. 139 (2017) 1037-1040.
[18] E. Hadjoudis, I. M. Mavridis, Photochromism and thermochromism of
Schiff bases in the solid state: structural aspects, Chem. Soc. Rev. 33 (2004)
579-588.
[19] Z. Zhou, S. Xie, X. Chen, Y. Tu, J. Xiang, J. Wang, Z. He, Z. Zeng, B. Z.
Tang, Spiro-functionalized diphenylethenes: suppression of a reversible
photocyclization contributes to the aggregation-induced emission effect, J. Am.
Chem. Soc. 141 (2019) 9803-9807.
[20] X. Wang, L. Guo, L. Feng, A multi stimuli responsive material with
rhodamine B and carbazole groups, New J. Chem. 43 (2019) 4181-4187.
[21] Z. Li, X. Li, H. Chen, C. He, L. Wang, Y. Yang, S. Wang, H. Guo, S.H.
Liu, Multi-modulated photochromic behavior of a D-A type dithienylethene,
Dyes Pigments 162 (2019) 712-720.
[22] A. Li, N. Chu, L. Huang, L. Han, Y. Geng, S. Xu, L. Pan, H. Cui, W. Xu,
Z. Ma, Remarkable responsive behaviors of iso-aminobenzopyranoxanthenes:
protonation effect, photochromism and piezochromism, Dyes Pigments 162
(2019) 831-836.
[23] K. Zheng, Q. Zou, Y. Yang, Y. Mao, J. Zhang, J. Cheng, The chromogen,
structure, inspirations, and applications of a photo-, pH-, thermal-, solvent-, and
17

Journal Pre-proof
mechanical-response epoxy resin, Ind. Eng. Chem. Res. 57 (2018)
13283-13290.
[24] Z. Ma, Y. Ji, Y. Lan, G.-C. Kuang, X. Jia, Two novel rhodamine-based
molecules with different mechanochromic and photochromic properties in solid
state, J. Mater. Chem. C 6 (2018) 2270-2274.
[25] L. Huang, Y. Qiu, C. Wu, Z. Ma, Z. Shen, X. Jia, A multi-state fluorescent
switch with multifunction of AIE, methanol-responsiveness, photochromism
and mechanochromism, J. Mater. Chem. C 6 (2018) 10250-10255.
[26] Q. Qi, J. Qian, S. Ma, B. Xu, S.X.A. Zhang, W. Tian, Reversible
multistimuli-response fluorescent switch based on tetraphenylethene-spiropyran
molecules, Chem. Eur. J. 21 (2015) 1149-1155.
[27] J. Guo, H. Yuan, D. Jia, M. Guo, Y. Li, Synthesis and improved
photochromic properties of pyrazolones in the solid state by incorporation of
halogen, Spectrochim. Acta. A. 171 (2017) 149-154.
[28] M.-J. Liu, J. Yuan, J. Tao, Y.-Q. Zhang, C.-M. Liu, H.-Z. Kou, Rhodamine
salicylaldehyde hydrazone Dy(III) complexes: Fluorescence and magnetism,
Inorg. Chem. 57 (2018) 4061-4069.
[29] Y. Li, K. Li, B.Z. Tang, A photoactivatable photochromic system serves as
a self-hidden information storage material, Mater. Chem. Front. 1 (2017)
2356-2359.
[30] Q. Feng, Y. Li, G. Shi, L. Wang, W. Zhang, K. Li, H. Hou, Y. Song, A
photo-controllable third-order nonlinear optical (NLO) switch based on a
rhodamine B salicylaldehyde hydrazone metal complex, J. Mater. Chem. C 4
(2016) 8552-8558.
[31] K. Li, Y. Xiang, X. Wang, J. Li, R. Hu, A. Tong, B.Z. Tang, Reversible
photochromic system based on rhodamine B salicylaldehyde hydrazone metal
complex, J. Am. Chem. Soc. 136 (2014) 1643-1649.
[32] K. Li, Y. Xiang, A. Tong, B.Z. Tang, Readily accessible rhodamine
B-based photoresponsive material, Sci. Chi. Chem. 57 (2014) 248-251.
18

Journal Pre-proof
[33] Z. Xu, L. Zhang, R. Guo, T. Xiang, C. Wu, Z. Zheng, F. Yang, A highly
sensitive and selective colorimetric and off-on fluorescent chemosensor for
Cu2+ based on rhodamine B derivative, Sensors Actuators B: Chem. 156 (2011)
546-552.
[34] Y. Xiang, A. Tong, P. Jin, Y. Ju, New fluorescent rhodamine hydrazone
chemosensor for Cu(II) with high selectivity and sensitivity, Org. Lett. 8 (2006)
2863-2866.
[35] Q. Feng, Y. Li, K. Li, J. Lu, J. Wang, P. Fan, D. Li, D. Wu, H. Hou,
Fluorescent chemosensor for zinc ion detection with significant emission color
change in aqueous solution based on AIEgen, ChemistrySelect 2 (2017)
3158-3162.
[36] M. Dong, T.-H. Ma, A.-J. Zhang, Y.-M. Dong, Y.-W. Wang, Y. Peng, A
series of highly sensitive and selective fluorescent and colorimetric “off-on”
chemosensors for Cu (II) based on rhodamine derivatives, Dyes Pigments 87
(2010) 164-172.
[37] A. Ganguly, S. Ghosh, S. Kar, N. Guchhait, Selective fluorescence sensing
of Cu(II) and Zn(II) using a simple Schiff base ligand: Naked eye detection and
elucidation of photoinduced electron transfer (PET) mechanism, Spectrochim.
Acta. A. 143 (2015) 72-80.
[38] F. Qian, C. Zhang, Y. Zhang, W. He, X. Gao, P. Hu, Z. Guo, Visible light
excitable Zn2+ fluorescent sensor derived from an intramolecular charge transfer
fluorophore and its in vitro and in vivo application, J. Am. Chem. Soc. 131
(2009) 1460-1468.
[39] Y. Li, K. Li, L. Wang, Y. He, J. He, H. Hou, B.Z. Tang, Fluoran
salicylaldehyde hydrazone Zn(II)complexes: reversible photochromic systems
both in solution and in a solid matrix, J. Mater. Chem. C 5 (2017) 7553-7560.
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Journal Pre-proof
Declaration of competing interests
☒ The authors declare that they have no known competing financial interests or personal
relationships that could have appeared to influence the work reported in this paper.
☐The authors declare the following financial interests/personal relationships which may be
considered as potential competing interests:
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Author Statement
Yuanyuan Li: Conceptualization, Methodology, Writing-Original draft preparation,
Funding acquisition.
Zining Feng: Data curation, Investigation.
Yajing Li: Investigation, Software, Validation, Data Curation.
Wenhui Jin: Visualization, Investigation.
Qiuchen Peng: Investigation, Formal analysis.
Panke Zhang: Conceptualization, Project administration, Writing-Reviewing and
Editing.
Juan He: Software, Validation.
Kai Li: Supervision, Funding acquisition, Writing-Reviewing and Editing
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Graphical abstract
Highlights
1. Photo-responsive properties of rhodamine B complexes were modulated by metal
ions.
2. Spirolactam ring in rhodamine B moiety turned open upon UV light irradiation.
3. The metal ions endowed the complexes with similar photochromic property.
4. But the metal ions induced the complexes distinctly different fluorescence change.
5. Logic gates were designed by simply varying the inputs of metal ions and UV
light.
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