A selectively rhodamine-based colorimetric probe for detecting copper(II) ion

Article abstract of DOI:10.1016/j.saa.2014.04.006

A novel rhodamine derivative 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH) has been synthesized by reacting rhodamine B hydrazide with 3-bromo-5-methylsalicylaldehyde and developed as a new colorimetric probe for the selective and sensitiv

Full text of DOI:10.1016/j.saa.2014.04.006

Accepted Manuscript
A selectively rhodamine-based colorimetric probe for detecting copper(II) ion
Jiangang Zhang, Li Zhang, Yanli Wei, Jianbing Chao, Shaomin Shuang,
Zongwei Cai, Chuan Dong
PII:
S1386-1425(14)00554-X
http://dx.doi.org/10.1016/j.saa.2014.04.006
SAA 11964
DOI:
Reference:
Spectrochimica Acta Part A: Molecular and Biomo-
lecular Spectroscopy
To appear in:
Received Date:
Revised Date:
Accepted Date:
13 January 2014
28 February 2014
2 April 2014
Please cite this article as: J. Zhang, L. Zhang, Y. Wei, J. Chao, S. Shuang, Z. Cai, C. Dong, A selectively rhodamine-
based colorimetric probe for detecting copper(II) ion, Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy (2014), doi: http://dx.doi.org/10.1016/j.saa.2014.04.006
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A selectively rhodamine-based colorimetric probe for detecting
copper(Ⅱ)ion
Jiangang Zhanga,b, Li Zhanga,b, Yanli Weia, Jianbing Chaoa, Shaomin Shuanga, Zongwei Caia, Chuan
Dong*a
aCollege of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, P.R. China
bSchool of Arts and Sciences, Shanxi Agricultural University, Taigu 030801, P.R. China
ABSTRACT
A novel rhodamine derivative 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH)
has been synthesized by reacting rhodamine B hydrazide with 3-bromo-5-methylsalicylaldehyde
and developed as a new colorimetric probe for the selective and sensitive detection of Cu2+.
Addition of Cu2+ to the solution of BMSRH results in a rapid color change from colorless to red
together with an obvious new band appeared at 552nm in the UV-vis absorption spectra. This
change is attributed to the spirocycle form of BMSRH opened via coordination with Cu2+ in a 1:1
stoichiometry and their association constant is determined as 3.2×104 Lꢀmol-1. Experimental results
indicate that the BMSRH can provide a rapid, selective and sensitive response to Cu2+ with a linear
dynamic range 0.667-240 µmol/L. Common interferent ions do not show any interference on the
Cu2+ determination. It is anticipated that BMSRH can be a good candidate probe and has potential
application for Cu2+ determination. The proposed probe exhibits the following advantages: a quick,
simple and facile synthesis.
Keywords: Rhodamine; Colorimetric; Probe; Copper; 3-bromo-5-methylsalicylaldehyde; Hydrazine
*
Corresponding authors: E-mail: dc@sxu.edu.cn (C. Dong); Tel: +86-351-7018613; Fax: +86-351-7018613.
1

1. Introduction
Copper is an essential transition element to human health. It is very important in various
physiological processes, such as bone formation, hematopoietic function, cellular respiration,
prevention of cardiovascular diseases and connective tissue development [1]. Copper, together with
certain protein, can also produces numerous critical enzymes for life such as cytochrome c oxidase,
tyrosinase and superoxide dismutase [2-5]. A deficiency of copper( ) can lead to anemia and
arteriosclerosis, whereas excess copper can be harmful and even cause Alzheimer's and Parkinson's
diseases [6,7]. The U.S. Environmental Protection Agency (EPA) has set the maximum allowable
level of copper in drinking water at 1.3ppm [8]. In addition, copper( ) is also used as the plant
diseases treatment, colorant of china and as preservatives for wood and leather in industry. Its
potential toxic effects on human beings continue to be challenging problems throughout the world.
Consequently, effective detection of copper( ) in food, industrial and physiological samples is of
importance and considerable effort has been made toward the development of highly selective and
sensitive ways to detect copper( ) including atomic absorption spectrometry [9 -11], inductively
coupled plasma mass spectroscopy (ICPMS) [12], inductively coupled plasma atomic emission
spectrometry (ICP-AES) [13]. However, those methods are usually complicated, time-consuming,
and costly. Recently, Colormetric and fluorescent methods proved to be a more powerful
technique for ion detections because of their high selectivity and ease of fabrication. Many of these
systems consists of a large rigid ꢁ-conjugated system such as fluoresceins [14-16], coumarins
[17-20], quinolines [21], rhodamines [22-37], BODIPY dyes [38-40], calixarenes [41-44],
polythiophene [45] and they have the obvious spectra absorption or strong fluorescence. Tangꢂs [46]
group have developed the first near-infrared fluorescent probe toward Cu2+ and successfully applied
to biological imaging. Compared with fluorimetry, Colormetry has its advantage due to the
2

simplicity and low capital cost of the assay, it is easy observation by the naked eye and no
requirement for sophisticated instruments. Shenꢂs [47] group and Yaoꢂs [48] group have also
developed a colorimetric method for the Cu2+ assay using click chemistry.
The fluorescein and rhodanmine family dyes are the ideal objectives for fabrication of
colorimetric sensors because of their distinctive structure. Ring-opening of their spirolactam
structure can lead to an obvious color change and a large rigid ꢁ-conjugated system with some
excellent spectroscopic properties, such as long absorption and emission wavelength, high
fluorescence quantum yield, visible-range extinction coefficients and high stability to light. By this
main feature, in recent years, fluorescein and rhodamine compounds are usually introduced to
construct optical sensor for many different target molecules especially transition metal ions, such as
Zn2+ [14], Cu2+ [15,16,23-29,37], Hg2+ [30-34], Fe3+ [35] and Pb2+ [36]. Given the importance of the
copper ions to our life, it is still desirable to develop some new probes for Cu2+ in terms of better
sensitivity and selectivity.
In the present study, we designed and synthesized a novel rhodamine-based compound,
3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH), for rapid, selective and
sensitive response to Cu2+ ion in acetonitrile and water media. The BMSRH bears a cleavable active
amide bond and exhibits a highly selective color reaction with Cu2+ in acetonitrile and water
solutions. Addition of Cu2+ to the solution of BMSRH results in a rapid color change from colorless
to red together with an obvious new band appeared at 552nm in the UV-vis absorption spectra.
Addition of other common alkali-, alkaline earth-, trasition- and rare earth metal ions had not any
changes in color or UV-vis absorption spectra. BMSRH is a naked-eye chemosensor for detection of
Cu2+ with facile, fast and selective features.
3

2. Experimental
2.1. Chemicals and Instruments
Rhodamine B and 3-bromo-5-methylsalicylaldehyde was purchased from Aladdin Chemical Co.,
Ltd. (Shanghai, China), hydrazine hydrate(85%, Beijing Xudong Chemical Plant), other material for
synthesis were used without further purification. All chemicals used were analytical grade.
Deionized water was used throughout the work.
Absorption spectra were taken on a TU-1901 double-beam UV–vis absorption spectrophotometer
(Beijing Purkinje General Instrument Co., LTD, Beijing, China). Fluorescence spectra were
recorded on a Cary Eclipse spectrofluorometer equipped with a 150 W xenon lamp source (Varian
Australian PTY LTD, Victoria, Australia). Quartz cuvettes (path-length=1cm) was used in all
1
spectrophotometric and fluorometric measurements. H NMR and 13C NMR measurements were
performed on a Bruker DKX-300MHz NMR spectrometer ( Bruker biospin, Switzerland). Mass
spectroscopy was performed on VG Micro mass 7070H(ESI-MS). All the spectra were recorded at
298K. Elemental analyses were done on a Vario EL cube elemental analyzer (Elementar, Germany).
Melting points were determined on a RD-1 melting point detector (Guoming, China).
2.2. Synthesis procedure
2.2.1. Synthesis of Rhodamine B hydrazide
Rhodamine B (4.79g, 10 mmol) was stirred in 50 mL of ethanol and excess hydrazine (12 ml,
hydrazine content > 80%) was added dropwise. Then the reaction mixture was heated to reflux for
5h with stirring and monitoring with TLC, during which time the pink color disappeared gradually.
After cooling to room temperature the solvent was removed on a rotary evaporator. The residue was
dissolved in HCl (1M) and adjusted the solution to pH 7 by 0. 5 M NaOH. The resulting precipitate
was filtered and washed many times with water to provide 3.94 g of RH as an off-white powder in
4

80% yield. 1H NMR (DMSO-d6, 300 MHz): ꢃ = 7.76 (m, 1H, ArH), 7.46 (m, 2H, ArH), 6.98
(m, 1H, ArH), 6.37–6.32 (d, 6H, xanthene-H), 4.27 (s, 2H, NH2), 3.32(q, 8H, NCH2CH3), 1.07 (t,
12H, NCH2CH3); 13C NMR (DMSO-d6) ꢃ = 12.46, 43.7, 64.76, 97.42, 105.46, 107.79, 122.16,
123.51, 127.72, 128.12, 129.63, 132.39, 148.11, 151.9, 153.04, 165.29. MS, m/z: 457.2 ( [RH +
H]+), 479.1 ([RH + Na]+); [RH] calculated 456.2.
2.2.2. Synthesis of 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH)
BMSRH was synthesized by reaction of Rhodamine
B
hydrazide with
3-bromo-5-methylsalicylaldehyde in ethanol containing catalytic amount of acetic acid. To a
solution of rhodamine hydrazide (0.99 g, 2 mmol) dissolved in 20 mL ethanol,
3-bromo-5-methylsalicylaldehyde (0.42g, 2 mmol) was added. The reaction mixture was heated to
reflux for 8 h with stirring and monitoring with TLC, After the reaction, the mixture was cooled and
an off-white precipitate appeared. The precipitate was separated by filtration and the crude product
was recrystallized using methanol to provide 1.06 g of BMSRH as an off-white powder in 75%
o
1
yield. Melting point: 153-154 C. H NMR (DMSO-d6, 300 MHz, 25℃): ꢃ 11.19 (s, 1H), 8.91 (s,
N=C-H, 1H), 7.92(1H), 7.60(2H), 7.36(1H), 7.02(2H), 6.45-6.35(6H), 3.32(8H), 1.05(12H). 13C
NMR (DMSO-d6, 75 MHz, 25℃): ꢃ (ppm):11.55, 18.54, 42.84, 64.68 (Cspiro), 96.58, 103.36,
107.48, 108.84, 118.05, 122.40, 123.10, 126.84, 127.23, 128.22, 128.95, 129.83, 133.50, 134.19,
147.33, 147.84, 149.55, 150.32, 150.84, 151.80, 162.87. MS, m/z: 654.3( [BMSRH + H]+), 676.3
([BMSRH + Na]+); [BMSRH] calculated 653.3.
2.3. Cu2+ sensing measurement
A standard Cu2+ solution (2.0×10-3 mol/L) was prepared by dissolving copper chloride in
deionized water. BMSRH stock solution (1.0×10-4 mol/L) was prepared in acetonitrile solution. In
5

detection, BMSRH was diluted to 2.4×10-5 mol/L by B-R buffer (pH = 7.0). Each time 3.0 mL of
2.4×10-5 mol/L BMSRH was placed into a 1.0 cm path-length silica cuvette, and the required
quantity of Cu2+ solution was added by a micro-pipette. 1 mins later the UV-vis spectra was
measured. All the measurements were taken at room temperature. For the interference detection,
solutions of Fe2+, Co2+, Zn2+, Cr3+, Pb2+, Ni2+, Sn2+, Hg2+, Mn2+, Al3+, Ba2+, Mg2+, Cu2+, and Fe3+
2-
from their chloride salts, Ag+ from its nitrate salt and Cr2O7 from their sodium salts were used.
2.4. Job’s plot measurements
1.0 × 10-4 mol/L stock solution of BMSRH in acetonitrile and a 1.0 × 10-4 mol/L stock solution
of Cu2+ in H2O were prepared, the stock solution of BMSRH and the Cu2+ stock solution were
placed in a test tube to obtain a total volume of 3.6 mL, then diluted to 15 mL with acetonitrile / pH
= 7.0 B-R buffer to get the test solution (nine test solutions were got; for the first test solution, 0.36
mL stock solution of BMSRH and 3.24 mL stock solution of Cu2+ were used, then diluted to 15 mL
with pH = 7.0 B-R buffer; for the second test solution, 0.72 mL stock solution of BMSRH and 2.88
mL stock solution of Cu2+ were used; for the third test solution, 1.08 mL stock solution of BMSRH
and 2.52 mL stock solution of Cu2+ were used; until 3.24 mL stock solution of BMSRH and 0.36
mL stock solution of Cu2+ were used to get the ninth test solution). All the measurements were
performed with [BMSRH] + [Cu2+] =24 ꢄmol/L. The absorbances at 552 nm of these test solutions
were recorded.
3. Results and discussion
6

3.1. Design and synthesis of BMSRH
A colormetric or fluorescence based metal ion probe usually comprises two major components:
a chromophore and a ligand. Our considerations for synthesizing BMSRH are based on the facts: (1)
3-bromo-5-methylsalicylaldehyde can be readily reacted with amino of rhodamine hydrazide to
form schiffꢂs base and contribute to a good coordination oxygen atom. (2)when coordination takes
place, the spirocycle structure of rhodamine moiety will be opened and at the same time an obvious
color and spectra change will be observed due to the formation of a large rigid ꢁ-conjugated system.
Consequently, the BMSRH was synthesized by a simple two-step reaction for detecting Cu2+ (Fig. 1)
1
and confirmed by H NMR, 13C NMR spectroscopy, and MS. The existence of spirocyclic ring
structure in BMSRH was confirmed by the observation of 13C NMR resonances at 64.68 ppm.
Figure 1.
3.2. UV-vis spectra of interaction of BMSRH with Cu2+
The UV-visible absorption spectra of BMSRH in the presence of Cu2+ are displayed in Fig. 2.
The BMSRH had nearly no absorption over 552nm region, which was ascribed to the closed
spirolactam form of BMSRH. When Cu2+ was added into the solution of BMSRH, it can chelate
with BMSRH, induce ring-opening at C-N bond in spirolactam and generate a rhodamine-type
intermediate with a new absorption peak appeared at 552nm and its absorbance increased
gradually with the increase of Cu2+ concentration. Correspondingly, the solution of BMSRH
changed from colorless to red. The significant spectra and color change indicated that BMSRH was
a sensitive naked-eye indicator for Cu2+. The analytical characteristics of BMSRH to Cu2+ based on
the absorption spectra have also been exploited The results showed that the absorbance value
7

changes (ꢅA) as a function to the concentration of Cu2+ ion had a good linear range of 6.67×10-7 to
2.4×10-4 mol/L with the linear regression equation of ꢅA=4.45×104[Cu2+]-0.03438 (Fig. 3a).
Further, according to linear Benesi-Hildebrand expression (Fig. 3b), the measured absorbance value
[1/(A-A0)] at 552 nm varied as a function of 1/[Cu2+] in a good linear relationship (r=0.9964),
which was an indication that the composition of BMSRH/Cu2+ complex was 1:1[49,50]. The
stability constant given by the slope of the straight line (Benesi–Hildebrand method) was 3.2×104
mol/L, It could be seen that BMSRH formed stable complex with Cu2+.
Figure 2.
Figure 3.
3.3. Time-dependence in the detection process of Cu2+
To investigate the Cu2+ detection ability, time-dependence on the UV-vis absorption spectra of the
reaction systems was investigated (as shown in Fig. 4). Low, medium and high concentration of
Cu2+ standard solution in the linear range was tested. Upon addition various concentrations (2 ꢄM,
10ꢄM, 20ꢄM) of Cu2+, the interaction of BMSRH with Cu2+ was completed in less than 1 min. One
min later three absorbance at 552 nm of the system get to maximum and does not increase with
more reaction time, which indicated that the BMSRH could rapidly react with Cu2+ and the
spirocycle of BMSRH could be opened in a very short time under the experimental conditions. It
means the method could be used for real-time detection of Cu2+ and 1 mins was also selected as the
detection time in this paper.
Figure 4.
3.4. Job’s plot analyses
8

For further determination the stoichiometry between BMSRH and Cu2+, Job’s plot analyses was
also used (Fig. 5). A plot of absorbances versus the molecular fraction of
f
[BMSRH]/([BMSRH]+[ Cu2+]) was provided in Fig. 6. All the analyses were performed with
[BMSRH] + [Cu2+] = 24 ꢄmol/L. The maximum absorbance intensity was appeared when the
molecular fraction of Cu2+ was close to 0.5, which indicated a 1:1 stoichiometry of the BMSRH to
Cu2+ in the inclusion complex. It was consistent with the result of linear Benesi-Hildebrand
expression.
Figure 5.
3.5. Selectivity investigation
Selectivity is an important characteristic of an ion-selective chemosensor. To examine the
selectivity of BMSRH toward Cu2+, the effect of a wide range of environmentally and
physiologically active metal ions was investigated using the UV-vis spectra and the result were
shown in Fig. 6. Under the same conditions, in the presence of other competive metals, the BMSRH
has no absorption at 552nm and the color of solution has not any change. Only Cu2+ was present, a
strong new absorption peak appeared at 552nm, and the color of the solution changed from
colorless to red immediately. Furthermore, The possible interferences by other metal ions were
further assessed through competitive experiments, the UV-vis spectra were measured by the
treatment of 24 ꢄmol/L Cu2+ in the presence of 48 ꢄmol/L other interfering metal ions. As shown in
Fig. 6. The absorption spectra of BMSRH solutions had similarly influence with that of Cu2+ was
lonely present., the tested background ions showed almost no interference with the detection of
Cu2+.These results demonstrated that BMSRH showed excellent selectivity to Cu2+ over other
competitive cations and the detection of Cu2+ was hardly affected by these coexistent common
9

metal ions.
Figure 6.
3.6. Interaction mechanism of BMSRH binding to Cu2+
The proposed mechanisms of detection and the structures of the probes, both with and without
the addition of Cu2+ were shown in Fig. 7. As other rhodamine-based probes, BMSRH had
spirocycle and open-cycle forms, The spirocycle form was colorless and non-fluorescent. Addition
of Cu2+ makes the spirocycle open via coordination and obvious color with spectra change appear
(Fig. 9). On addition of EDTA to the solution of BMSRH containing Cu2+, the change of color and
spectra disappeared again, this process could be repeated many times. These findings indicated that
BMSRH reversibly coordinated with Cu2+, rather than other possible reactions. Ring-opening of the
spirocyle form resulted in a large rigid ꢁ-conjugated system but did not generate strong
fluorescence emission. This phenomenon was own to the paramagnetic effect from spin-orbit
coupling of the Cu2+ inducing fluorescence quenching of BMSRH. Similar phenomena were also
observed in other experiments [51-53].
Figure 7.
In order to better understand the reaction mechanism of BMSRH and Cu2+, C NMR titration
13
was performed to assess their interaction(Fig. 8). 13C NMR spectra of BMSRH–Cu2+ compared to
that of BMSRH showed the involvement of carbonyl oxygen of BMSRH in complex formation.
The reduction in the 13C-resonance at 64.68ppm confirms the opening of spirolactam ring upon
complex formation with Cu2+ ions. Meanwhile, new characteristic absorption peaks appeared at
552nm in the presence of Cu2+ proved the spirolactam moiety of rhodamine backbone ring-opening
because of the coordination of Cu2+ to BMSRH.
10

Figure 8.
3.7. Test of the method
The accuracy of this newly designed method was tested by recovery experiment. The solution of
Cu2+ was prepared to the concentration of 2 mmol/L by dissolving CuCl2·2H2O in water. Each time
3ml 24 ꢄmol/L BMSRH in CH3CN/H2O solution (1:1 v/v, 20 mmol/L B-R buffer at pH 7.0) was
placed into a 1.0 cm path-length silica cuvette. Low, medium and high concentration of Cu2+
standard in the linear range was then added into the BMSRH solution by a micro-pipette and the
concentration of Cu2+ were 2.00, 20 and 100 ꢄmol/L, respectively. After 1 min, the UV-visible
absorption spectrum was recorded. We obtained the found content of Cu2+ by the equation of
ꢅA=4.45×104[Cu2+]-0.03438 and the result were showed in Table 1. From the date, the original and
obtained contents were approximately consistent, and the RSD%﹤2%.Besides, From the results of
many times, the recovery of Cu2+ were kept within the range of 96%-103% and the average
recovery(%) was 97.70%, which indicated that the designed method was reliable. BMSRH could be
a potential candidate as a simple-to-use and naked-eye probe for Cu2+ determination.
Table 1
Conclusion
In summary, A novel rhodamine derivative BMSRH has been successfully synthesized by the
reaction of rhodamine B hydrazide and 3-bromo-5-methylsalicylaldehyde. Its sensing
characteristics to Cu2+ was further investigated using UV-vis spectroscopies. In the presence of Cu2+,
the BMSRH displayed an obvious color change from colorless to red together with UV-vis
absorption spectra change in a very short time. As the result of coordination of BMSRH with Cu2+
in a 1:1 stoichiometric ratio, their ring-opening reaction mechanisms were proposed. Futhermore,
11

BMSRH exhibited a good selectivity and sensitivity towards Cu2+ over other common competitive
alkali, alkaline earth and transition metal ions. The proposed probe exhibits the following
advantages: a quick, simple and facile synthesis. This phenomenon made the real-time,
simple-to-use and naked-eye detection of Cu2+ possible.
Acknowledgements
Financial supports from the National Natural Science Foundation of China (21175086) and
Natural Science Foundation for Young Scientists of Shanxi Province (2010021010-2) are gratefully
acknowledged. This work was also supported by the project of Hundred Talents Program of Shanxi
Province.
12

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15

CAPTIONS FOR FIGURES
Figure 1. Synthetic route for 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone
(BMSRH).
Figure 2. The UV-visible absorption spectra of BMSRH (24 ꢄmol/L, CH3CN/H2O=1:1) with
various concentrations of Cu2+ at room temperature. (a) [Cu2+]=1.33, 2.67, 4.0, 5.33, 6.67, 8.0,
9.33, 10.67, 12.0, 13.33, 14.67, 16.0, 17.33, 18.67, 20.0, 21.33, 22.67,and 24.0 ꢄmol/L, respectively;
(b) Inset image shows the corresponding colors change of BMSRH with the various concentrations
of Cu2+ in natural light.
Figure 3. (a)Linear range calibration curve of determination of Cu2+ ion. (b) Benesi-Hildebrand
plot of 1/(A-A0) versus 1/[Cu2+].
Figure 4. Time course of the response of BMSRH (22 ꢄmol/L, B-R buffer, pH=7.0) to (a)2.0
ꢄmol/L, (b)10 ꢄmol/L, (c)20 ꢄmol/L of Cu2+ in aqueous solution. Inset image shows the
corresponding colors change of BMSRH with the various concentrations of Cu2+ in natural light.
Figure 5. Job’s plot of BMSRH with Cu2+ in CH3CN/H2O=1:1 solution. Total concentration of
BMSRH + Cu2+ was kept constant at 24 ꢄmol/L. The absorbance at 552 nm was used.
Figure 6. UV-vis absorption spectra of BMSRH (24 ꢄmol/L, CH3CN/H2O=1:1) in the presence
of Cu2+ (24 ꢄmol/L) and other cations x (48 ꢄmol/L) including Cu2+, Al3+, Co2+, Ni2+, Fe3+, Fe2+,
2-
Zn2+, Ag+, Mg2+, Ba2+, Cr3+, Cr2O7 , Hg2+, Mn2+, Pb2+ , Sn2+. Inset:the Columns plot of BMSRH
(24 ꢄmol/L, CH3CN/H2O=1:1) in the different metal ions and the image of the corresponding colors
of BMSRH (24 ꢄmol/L, CH3CN/H2O=1:1) in natural light in the presence of different metal ions.
Figure 7. Proposed binding mechanism of BMSRH with Cu2+.
Figure 8. 13C NMR spectra of BMSRH in the absence or presence of Cu2+ (a) BMSRH, (b)
BMSRH + Cu2+.
16

Table 1 Test experiment determination of Cu2+.
Original content
of Cu2+ (ꢄmol/L)
found content
of Cu2+. (ꢄmol/L)a
RSD%
Recovery%
average recovery%
Day
2.00
2.00 0.08
20.00 0.48
100.00 1.29
2.00 0.06
2.06
0.82
0.48
1.92
0.66
0.52
96 – 102.0
97.6 – 102.4
98.7 – 111.2
97.0 – 103
20.00
100.00
2.00
97.7
Days
20.00
100.00
20.00 0.52
100.00 1.18
97.4 – 102.5
98.8 – 111.8
a Every concentration were determinated 8 times
17

Figure 1
18

Figure 2
1.0
0.8
0.6
0.4
0.2
0.0
2+
[Cu
]
300
400
500
600
Wavelength(nm)
19

Figure 3
1.0
0.8
0.6
0.4
0.2
0.0
12
10
8
b
a
y=4.45× 104 x-0.03438
r=0.9986
r=0.9964
6
4
2
0
0.0
0.1
0.2
0.3
0.4
0.5
0
5
10
15
20
-6
Cu2+](×10 mol/L
)
2+
1/[Cu](×10mol/L)
6
[
20

Figure 4
c
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
a
b
c
b
a
0
5
10
15
20
Time(min)
21

Figure 5
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0.2
0.4
[C u 2 +
[C u 2 + ] + [B M S R H ]
0.6
0.8
1.0
]
22

Absorbance
Absorbance
BMSRH
Cu(Ⅱ)
Al(Ⅲ)
Co(Ⅱ)
Ni(Ⅱ)
Fe(Ⅲ)
Fe(Ⅱ)
Zn(Ⅱ)
Ag(Ⅰ)
Mg(Ⅱ)
Ba(Ⅱ)
Cr(Ⅲ)
Cr(Ⅵ)
Hg(Ⅱ)
Mn(Ⅱ)
Pb(Ⅱ)
Sn(Ⅱ)

Figure 7
24

Figure 8
Current Data Parameters
NAME
bbi13c1312
EXPNO
PROCNO
24
1
F2
Date_
Time
-
Acquisition Parameters
20131225
10.49
INSTRUM
PROBHD
PULPROG
TD
drx300
mm Multinucl
5
zgdc
65536
DMSO
22178
0
SOLVENT
NS
DS
ꢡꢢꢣꢋꢉ
SWH
22675.736 Hz
FIDRES
AQ
RG
0.346004 Hz
1.4451188 sec
9195.2
DW
DE
TE
D1
d11
TD0
22.050 usec
6.00 usec
291.9 K
2.00000000 sec
0.03000000 sec
1
======== CHANNEL f1 ========
NUC1
P1
13C
9.50 usec
0.00 dB
PL1
SFO1
75.4752960 MHz
======== CHANNEL f2 ========
CPDPRG2
NUC2
waltz16
1H
ꢟꢚꢠꢜꢔꢕ
PCPD2
PL2
PL12
80.00 usec
6.00 dB
24.06 dB
300.1315010 MHz
SFO2
F2
SI
-
Processing parameters
32768
SF
75.4676586 MHz
EM
WDW
SSB
LB
GB
PC
0
10.00 Hz
0
1 6 0
1 4 0
1 20
1 0 0
80
6 0
4 0
2 0
p p m
1.40
Current Data Parameters
NAME
bbi13c1312
EXPNO
PROCNO
26
1
F2
-
Acquisition Parameters
Date_
Time
20131226
14.50
INSTRUM
PROBHD
PULPROG
TD
SOLVENT
NS
drx300
mm Multinucl
5
zgdc
65536
DMSO
70000
0
ꢡꢢꢣꢋꢉ ꢟꢏꢤ
DS
SWH
22675.736 Hz
FIDRES
AQ
0.346004 Hz
1.4451188 sec
9195.2
RG
DW
DE
22.050 usec
6.00 usec
TE
292.4
K
D1
2.00000000 sec
d11
0.03000000 sec
1
TD0
======== CHANNEL f1 ========
NUC1
P1
13C
9.50 usec
PL1
SFO1
0.00 dB
75.4752960 MHz
======== CHANNEL f2 ========
CPDPRG2
NUC2
waltz16
1H
PCPD2
PL2
80.00 usec
6.00 dB
24.06 dB
PL12
ꢟꢚꢠꢜꢔꢕ
SFO2
300.1315010 MHz
F2
-
Processing parameters
SI
32768
SF
75.4676586 MHz
WDW
SSB
LB
EM
0
10.00 Hz
0
1 6 0
1 4 0
1 2 0
1 0 0
8 0
6 0
4 0
2 0
GB
p p m
PC
1.40
25

26

A novel rhodamine B derivative 3-bromo-5-methylsalicylaldehyde rhodamine B
hydrazone (BMSRH) was synthesized and characterized.
BMSRH have a rapid, selective and sensitive response to Cu2+.
The response of BMSRH to Cu2+ is reversible .
BMSRH can be a good colorimetric probe for Cu2+ determination .
27