Luminescent Coordination Polymers for Highly Sensitive Detection of

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Crystal Growth & Design

Luminescent Coordination Polymers for Highly Sensitive Detection of Nitrobenzene Beibei Liu, Xiaoling Lin, Hao Li, Kaixuan Li, Hui Huang, Liang Bai, Hailiang Hu*, Yang Liu* and Zhenhui Kang Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China ABSTRACT

Three new luminescent coordination polymers (CPs), [Ag2(bpp)(Hsba)]·H2O (1), [Cd(bpp)(Hsba)·H2O] (2) and [Pb(bpp)3(H2sba)2] (3) (bpp = 1,3-bis(4-pyridyl)propane, H3sba = 2,4-dichloro-5sulfamoylbenzoic acid) have been designed and synthesized by hydrothermal methods. Compound 1 exhibits left- and right-handed helical chains. Compound 2 shows a 2-fold parallel interpenetration sql net with 44·62 topology. Compound 3 displays a supramolecular wave-like chain. These three title CPs are used as fluorescence sensors for highly selective and sensitive detection of nitrobenzene in a wide linear detection range.

INTRODUCTION Nitrobenzene (NB), a simple nitro aromatic compound, is widely used in the chemical synthesis of the dyes, aniline, pesticides and explosives.1,2 However, NB is a highly toxic pollutant with carcinogenicity, recalcitrance and accumulation in the environment.3–5 Hence, sensitive and selective detection of NB has become a pressing issue in chemical industry, as well as environmental problems. In recent years, ACS Paragon Plus Environment


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canines,6 gas chromatography coupled with mass spectrometry,7 ion mobility spectroscopy (IMS),8 Xray dispersion,9 Raman spectroscopy10 and electrochemical method11,12 have been used to detect NB. These methods are not always convenient and available because of the high cost and frequent careful calibrations for instruments. Therefore, it’s imperative to seek a simple, inexpensive and sensitive method for detection of NB. Recently, luminescent coordination polymers (CPs) have been proven as fluorescence sensors for detection of NB due to their selectivity, sensitivity, quick response, operability and reversibility. Most of CPs realize sensitive performance via a redox fluorescence quenching mechanism.13–15 For example, Ruan et al. reported a luminescent coordination polymer, which was used as a sensor for detection of NB with a detection limit of 5 ppm.14 Shi et al. reported a luminescent metal–organic framework that was able to detect NB with a detection limit of 50 ppm.15 However, many of previous reported CPs have their drawbacks of low sensitivity and narrow linear detection range.13–17 Therefore, it is still a huge challenge to construct CPs as fluorescence sensors for NB with a lower detection limit and wider linear detection range. It is known that introduction of rich electron–donor ligands could efficiently construct luminescent CPs. In our previous works, we have demonstrated that electron–donor 2,4-dichloro-5-sulfamoylbenzoic acid (H3sba) and its analogue (4-chloro-5-sulphamoylbenzoic acid) could induce the synthesis of luminescent CPs, which exhibit good and tunable luminescent properties.18,19 In addition, H3sba possesses multi-coordinating groups (one carboxylate and one sulphonylamino groups, two Cl atoms), which could generate different coordination modes and satisfy the construction of diverse structures. Here, H3sba is chosen as ligand and three new luminescent CPs [Ag2(bpp)(Hsba)]·H2O (1), [Cd(bpp)(Hsba)·H2O] (2) and [Pb(bpp)3(H2sba)2] (3) are synthesized. We demonstrate here the three title compounds can be used as excellent sensors for detection of NB with high selectivity, sensitivity, stability and recyclability. The emission intensity gradually quenched with the increase of the NB concentration. For 1 and 2, the detection limits are 0.33±0.02 and 0.53±0.08 ppm, respectively. While 3 represents the lowest detection limit of (1.66±0.16)×10-3 ppm with a correlation coefficient of 0.998 in

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the range of (1.66±0.16)×10-3 to 700±2.25 ppm. A series of anti-interference experiments suggest that the interferences of other organic solvents on the fluorescence response of 1–3 are very limited. EXPERIMENTAL SECTION Materials and general methods. All analytical reagents were purchased from commercial sources and used without further purification. Elemental analyses of C, H and N were performed using an EA1110 elemental analyzer. The IR spectra were recorded in the range 4000–400 cm-1 on a Nicolet 360 spectrometer with a pressed KBr pellet. The TG-DTA analyses were carried out by Universal Analysis 2000 thermogravimetric analyzer (TGA) in N2 with a heating rate of 10°C min-1 from 30 to 800°C. The crystal structures of the resultant products were characterized by X-ray powder diffraction (XRD) by using an X‘Pert-ProMPD (Holand) D/max-γAX-ray diffractometer with Cu Kα radiation (λ = 0.154178 nm). Crystal data were collected on a Bruker X8 APEX II-CCD single crystal X-ray diffractometer with Mo Kα radiation (λ = 0.71073 Å). The UV-vis spectra were carried out on an Agilent 8453 UV-VIS Diode Array Spectrophotometer.

Luminescent

spectra

were

collected

on

a

Fluoromax-4

spectrophotometer. All the detections were repeated more than three times to ensure the accuracy. Synthesis of [Ag2(bpp)(Hsba)]·H2O (1). A mixture of AgAc (0.05 g, 0.30 mmol), H3sba (0.04 g, 0.15 mmol) and bpp (0.03 g, 0.15 mmol) in 10 mL H2O was stirred for 30 min. When the pH value was adjusted to 8.4 with 1.0 M aqueous ammonia, the mixture was sealed in a 25 mL Teflon-lined autoclave and then heated at 130°C for 3 days under autogenous pressure. After cooling to room temperature, colorless crystals were formed and washed with deionised water, and then dried in air. Yield: 36.75 mg, 0.05 mmol, 35% (based on Ag). Anal. Calcd (%) for C20H19Ag2Cl2N3O5S: C, 34.28; H, 2.71; N, 6.00. Found: C, 34.31; H, 2.72; N, 5.58. Synthesis of [Cd(bpp)(Hsba)·H2O] (2). Compound 2 was prepared in a manner similar to that for 1, but Cd(Ac)2·2H2O (0.08 g, 0.30 mmol) was used instead of AgAc. The pH value was adjusted to 10.0 with 1.0 M aqueous ammonia and/or hydroxide solution. After cooling to room temperature, pink block crystals were formed and washed with deionised water, and then dried in air. Yield: 82.35 mg, 0.14



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mmol, 46% (based on Cd). Anal. Calcd (%) for C20H19CdCl2N3O5S: C, 40.22; H, 3.18; N, 7.04. Found: C, 40.19; H, 3.22; N, 7.03. Synthesis of [Pb(bpp)3(H2sba)2] (3). Compound 3 was prepared in a manner similar to that for 1, but Pb(Ac)2·3H2O (0.11 g, 0.30 mmol) was used instead of AgAc. The pH value was adjusted to 6.8 with 1.0 M hydroxide solution. After cooling to room temperature, pink block crystals were formed and washed with deionised water, and then dried in air. Yield: 56.29 mg, 0.04 mmol, 14% (based on Pb). Anal. Calcd (%) for C53H50Cl4N8O8PbS2: C, 47.46; H, 3.73; N, 8.36. Found: C, 47.38; H, 3.80; N, 8.29. X-ray Crystallographic Study. Diffraction measurements were performed at 296 K on a Bruker Smart Apex CCD diffractometer using Mo Kα radiation (λ = 0.71073 Å). The structures were solved by direct method with SHELXS and refined by full-matrix least squares on F2 with SHELXL.20 Anisotropic thermal parameters were used to refine all non-hydrogen atoms. Hydrogen atoms were generated theoretically and fixed to ride on the parent carbon and nitrogen atoms. In 1, hydrogen atoms attached to free water molecules (O1W) were not located and were included in the molecular formula directly. A summary of the crystallographic data and structure refinement details is given in Table 1. Selected bond distances and angles are listed in Table S1. Hydrogen-bonding parameters are summarized in Table S2. CCDC numbers are 1058271–1058273 for 1–3, respectively. Table 1. Crystal data and structural refinements for 1–3 1

2

3

Empirical formula

C20H19Ag2Cl2N3O5S

C20H19CdCl2N3O5S

C53H50Cl4N8O8PbS2

Formula weight

700.08

596.74

1340.12

Crystal system

Monoclinic

Monoclinic

Orthorhombic

Space group

P21/c

C2/c

Pccn

a (Å)

12.1651(5)

17.6418(18)

15.2758(10)

b (Å)

9.7980(4)

10.6360(11)

38.796(3)

c (Å)

20.6387(7)

22.861(2)

9.4218(6)

β (°)

113.010(2)

93.865(2)

90.00


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V (Å3)

2264.28(15)

4279.8(7)

5583.7(7)

Z

4

8

4

Dc (g/cm3)

2.054

1.852

1.594

µ (mm-1)

2.097

1.408

3.348

F (000)

1376.0

2384.0

2680.0

Collcd reflns

11605

11120

27446

Unique reflns

3976

3753

4903

Parameters

298

289

350

Rint

0.0212

0.0412

0.0419

GOF

1.035

1.032

1.055

R1a [I>2σ (I)]

0.0274

0.0268

0.0321

wR2b (all data)

0.0733

0.0594

0.0650

a

R1 = Σ||F0|–|Fc||/Σ|F0|, b wR2 = Σ[w(F02–Fc2)2]/Σ[w(F02)2]1/2.

RESULTS AND DISCUSSION Synthesis. The target compounds were synthesized by hydrothermal reactions of metal salts (Ag+, Cd2+ and Pb2+), H3sba and bpp with the same molar ratio of 2:1:1. Parallel experiments show that the products are heavily dependent on the pH modifiers. For 1 and 3, high-quality crystals could only be collected by using aqueous ammonia and hydroxide solution as modifiers, respectively. For 2, optimal pH modifiers of the reaction are hydroxide solution and aqueous ammonia. When other weak bases are used, such as ethylenediamine and triethylamine, only some amorphous precipitates are obtained, suggesting that the pH modifier is a determining factor in construction of the products. In the three title compounds, the carboxylate groups are completely deprotonated and coordinated to metal centers via monodentate and/or chelating modes. Simultaneously, the sulphonylamino groups also respond to different metal centers actively. In 1 and 2, the sulphonylamino groups are deprotonated and coordinated to Ag and Cd atoms, whereas in 3, the sulphonylamino group is in the neutral state and supplies potential sites for supramolecular interactions. ACS Paragon Plus Environment


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Description of the crystal structures. [Ag2(bpp)(Hsba)]·H2O (1). Compound 1 crystallizes in the monoclinic system, space group P21/c. The asymmetric unit contains two Ag atoms, one Hsba2− ligand, one bpp ligand and one free water molecule (Figure S1a). In 1, the bpp ligand exhibits a trans-trans (TT) conformation (Table S3), providing an N-to-N distance of 9.4702(40) Å and the dihedral angle between the pyridyl rings of 86.850(101)°. The bpp ligands link Ag atoms by Nbpp atoms, producing a one dimensional (1D) wave-like [Ag(bpp)]nn+ chain. The neighboring [Ag(bpp)]nn+ chains are interconnected to each other, forming a two dimensional (2D) layer through Ag–Ag bonds (3.0138(6) Å),21–23 as shown in Figure 1a. The Hsba2− ligands connect Ag atoms via one sulphonylamino N (Nsul) and one carboxylate O (Ocar) atoms, forming left- and right-handed helical [Ag(Hsba)]nn− chains (Figure 1b) with the same pitch of 9.7980(6) Å. The chains running along b-axis are sandwiched by the 2D layers constructing a multi-sandwiching supramolecular structure (Figure 1c). Interestingly, both of the left- and right-handed helical chains are anchored by the adjacent layers through weak interactions between Ag atoms and sulphonylamino groups (Figure S1b).


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Figure 1. (a) The 2D layer constructed by [Ag(bpp)]nn+ chains in 1. Hydrogen atoms are omitted for clarity. (b) The left- and right-handed helical chains. (c) An idealized view of the sandwichlike structure in 1. Yellow, red and green colors represent the 2D layers, left- and right-handed helical chains, respectively.


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[Cd(bpp)(Hsba)·H2O] (2). Compound 2 crystallizes in the monoclinic system, space group C2/c. The asymmetric unit contains one Cd atom, one Hsba2− ligand, one bpp ligand and one coordinated water molecule. The Cd atom exhibits a distorted octahedral geometry of [CdO3N3] coordinated by two Nbpp atoms, one Nsul atom, two chelating Ocar atoms and one water molecule (Figure S2a). As shown in Figure 2a, two crystallographically equivalent Cd2+ ions are connected by two Hsba2− ligands to form a 16-membered dinuclear macrocycle, which serves as a secondary building unit (SBU) with distance of 6.8614(6) Å for nonbonding Cd···Cd. The bpp ligand adopts trans-gauche (TG) conformation (Table S3), providing an N-to-N distance of 9.1829(32) Å and the dihedral angle between the pyridyl rings of 69.303(81)°. The SBUs are further linked by bpp ligands to form a 2D grid-like layer (Figure 2b). Topologically, each dinuclear SBU can be simplified as a 4-connected node and bpp as a linear linker. Then the layer can be simplified as a uninodal sql net with 44·62 topology (Figure 2c). The net shows large rhombic windows with dimensions of 15.6135(10)×15.6135(10) Å2 between adjacent centers of SBUs. Interestingly, these large windows offer a good chance for the interpenetration between two identical layers to form parallel 2D → 2D layers,24,25 as shown in Figure 2d. Furthermore, the 2-fold parallel interpenetration is reinforced by the hydrogen bonding and CH–π interactions (Figure S2b) between the two single layers. In the packing arrangement, these bilayers are parallel to each other to give a three dimensional (3D) supramolecular structure.


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Figure 2. (a) View of the dinuclear Cd unit. Hydrogen atoms are omitted for clarity. (b) The 2D layer constructed by SBU and bpp. (c) Topological representation of the 2D net. (d) The 2-fold parallel interpenetration of the 2D layers. [Pb(bpp)3(H2sba)2] (3). Compound 3 crystallizes in orthorhombic system, space group Pccn. The asymmetric unit contains one Pb atom, one H2sba− ligand and one and a half of bpp ligands. The Pb center is six-coordinated by two Nbpp atoms and four chelating Ocar atoms to form a hemidirected coordination geometry (Figure S3). The bpp ligand adopts TT conformation (Table S3) with an N-to-N distance of 9.9423(65) Å and the dihedral angle between the pyridyl rings of 70.890(18)°. Two H2sba− and two bpp ligands connect one Pb atom forming a mononuclear [Pb(H2sba)2(bpp)2] unit (Figure 3a). Neighboring units are further linked through a pair of hydrogen bonds (N(1)–H(1B)···N(3), 2.05(5) Å) to produce a wave-like chain (Figure 3b). Furthermore, adjacent chains are parallel arranged and linked through the guest bpp ligands by


9


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hydrogen bonds (N(1)–H(1A)···N(4), 2.24(5) Å), resulting in a 2D supramolecular sheet (Figure 3c).

Figure 3. (a) The [Pb(H2sba)2(bpp)2] unit of 3. Hydrogen atoms are omitted for clarity. (b) Wave-like chain constructed by mononuclear units. (c) 2D supramolecular sheet formed by 1D chains and guest bpp ligands. Luminescence behaviors and sensing properties. The UV-vis absorption spectra of compounds 1–3 together with the free H3sba ligand at room temperature are shown in Figure 4a. Bpp shows absorption with peaks at 210, 249 and 274 nm.26 H3sba exhibits strong absorption in the range of 275–310 nm with two peaks at 280 and 290 nm, which may be ascribed to n–π* or π–π* transition.18,19 Compounds 1–3 display a similar strong absorption in the range of 275–310 nm, which may originate from the intraligand charge transfer transition. Whereas, the lower energy band from 360 to 800 nm for 1 and 2 can be considered as metal-to-ligand charge transfer transition.27,28 Solid-state emission spectra of 1–3 were measured at room temperature to study their potential as luminescent materials. The excitation and emission spectra of 1–3 are shown in


10

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Figure 4b and 4c. H3sba exhibits a weak emission peak at 455 nm and an intense emission peak at 545 nm.18 Free bpp ligand shows emission at 446 nm.29,30 Upon excitation at 314, 312 and 310 nm, compounds 1–3 display luminescence emissions centered at 412, 420 and 407 nm, respectively, which are attributed to intraligand charge transfer of H3sba.31,32 All of emissions of 1–3 are significantly blue-shifted relative to that of free H3sba, which may be assigned to the coordination of metal ions to ligands.33,34

Figure 4. (a) The UV-vis absorbance spectra of free H3sba ligand and 1–3. (b) Solid-state excitation spectra and of 1–3 with normalized intensities. (c) Solid-state emission spectra of 1–3 with normalized intensities. In order to study the potential luminescence sensing application of the three CPs for detection of NB, the luminescent properties of these CPs dispersed in common solvents were investigated. The

solvents

are

methanol,

ethanol,

isopropanol,

CH2Cl2,

CHCl3,

DMF

(N,N′-

dimethylmethanamide), acetonitrile, acetone, phenylmethanol, toluene and nitrobenzene. Here, the fluorescence measurements of compound 3 will be described in detail. Before the fluorescence study, a finely ground powder sample of 3 (3 mg) was immersed in different organic solvents (3 mL), treated by ultrasonication for 30 min and then aged for 3 days to form stable suspensions. As shown in Figure S4a, the suspension of 3 in NB shows the significant luminescence quenching effect. The results indicate that 3 has a selective response to NB. The possible luminescence quenching is photoinduced electron-transfer mechanism, that is, the


11


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excited state electron of electron rich 3 would undergo a transfer to electron withdrawing NB.14,35,36 To further investigate the sensitivity of fluorescence quenching by NB in detail, the emissive response was monitored by recording the fluorescence intensity of a series of suspensions of 3 in acetonitrile with gradually increasing NB concentration. As shown in Figure 5a, the emission intensity decreases continuously with increasing NB concentration. Detailed fluorescence quenching titrations are shown in Figure S4b. The ratio I0/I is used to evaluate the sensing sensitivity of 3, where I0 and I are the maximum fluorescence intensity of 3 before and after adding NB, respectively. It is observed that I0/I is proportional to the NB concentration with a good linear correlation (R2 = 0.998), as shown in Figure 5b. We can see that the limit of detection is (1.66±0.16)×10-3 ppm. Upon the addition of 700 ppm NB, the luminescence intensity is nearly completely quenched with a high quenching efficiency of 89.90±1.80% (quenching efficiency is defined as (1–I/I0)×100%). The results suggest that the sensitivity of 3 in detecting the presence of NB is comparable to or higher than other reported structures.14,37,38


12

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Figure 5. (a) The emission spectra of dispersed 3 in acetonitrile in the presence of a series of concentrations of NB. (CNB = 0, 2.75, 33, 69.73, 177.88 and 700 ppm). Insert: the histograms of corresponding fluorescence intensity. (b) The relationship between I0/I and NB concentration with a linear regression equation being I0/I = 1.115 + 0.012 CNB. CNB = nitrobenzene volume concentration, ppm. The anti-interference ability of 3 as sensor was also investigated by adding possible interfering organic pollutants in its acetonitrile suspensions. As shown in Figure 6a, addition of different organics displays no obvious influence on the emission of 3. However, the emission intensities of


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above suspensions are remarkably decreased with the subsequent addition of NB. These results imply that 3 has excellent anti-interference ability. The highly sensitive detection of NB at low concentration indicates that 3 could be able to detect trace NB vapour. Hence, we implemented the real-time solid-gas sensing of NB vapour. The vapor-sensing experiment was performed by using a home-made device (Figure S5).38 The fluorescence intensity of 3 is quenched by 74.45±1.31% when exposed to NB vapor for 15 s and quenched by 89.38±2.10% for 850 s, as shown in Figure 6b. The results suggest that 3 is highly sensitive for detection of trace amounts of NB in the vapor phase.38,39


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Figure 6. (a) Fluorescence intensity ratio (I/I0) histograms of 3 dispersed in acetonitrile with the addition of different organic solvents (red) and subsequent addition of NB (blue). (b) Timedependent fluorescent spectra of 3 upon exposure to NB vapour. In order to confirm fluorescence stability, effects of temperature and stabilization time on the fluorescence intensity of 3 were studied. From Figure 7a, we can see that the fluorescence intensity of 3 displays no obvious change when the temperature increases from 10°C to 40°C. Figure 7b shows that fluorescence intensity of 3 maintains stable over 5 hours. The results reveal that the temperature and stabilization time display no obvious effect on the fluorescence intensity. In addition, a series of sensing and recovery experiments reveal that 3 is stable and still retains sensitive property after five cycles (Figure 7c). The PXRD patterns of isolated samples of 3 immersed in acetonitrile in the presence of NB are similar to that of initial sample, suggesting that 3 retains the original structure (Figure 7d). All the results reveal that 3 is a promising candidate for detection of NB.


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Figure 7. The effects of temperature (a) and stabilization time (b) on the fluorescence intensity (black and red lines represent the emission intensity of 3 mg compound 3 in 3 mL acetonitrile and with addition of 700 ppm NB, respectively). (c) The relationship between fluorescence intensity and recycling times of 3 as a sensor for five times. 3 was reused by centrifugation, washing several times with acetonitrile and slow evaporation. Purple and green histograms represent the intensity of 3 dispersed in acetonitrile and upon adding 700 ppm NB, respectively. (d) XRD spectra of 3: simulated (dark line), as-synthesized (red line), after 1 (blue line), 2 (dark cyan line), 3 (magenta line), 4 (dark yellow line) and 5 (navy line) times recycling. For compounds 1 and 2, the sensitive and selective detection abilities for NB were also investigated and the detailed data were shown in Figure S6, S7 and S8. 1 and 2 show low detection limits of 0.33±0.02 and 0.53±0.08 ppm over wide linear detection ranges, respectively, which are comparable to other reported structures.14,37,38 A summary of detailed luminescence detection data for 1–3 is shown in Table 3. The experimental data show that 3 exhibits the lowest detection limit and the best linear relationship between I0/I and the NB concentration. Due to the highly sensitive detection of NB, the sensing abilities of compounds 1–3 toward other nitro compounds have also been investigated, as shown in Figure S9. The fluorescence quenching behaviors demonstrate that compounds 1–3 also possess potential application in sensing of other nitro compounds. Table 3. A summary of the detailed luminescence data along with standard deviations of 1– 3 for detection of NB Limit of detection for Linear detection range (ppm) Correlation coefficient NB (ppm) 1

0.33±0.02

(0.33±0.02)–(5689±7.61)


0.990

16

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2

0.53±0.08

(0.53±0.08)–(570±2.48)

0.992

3

(1.66±0.16)×10-3

(1.66±0.16)×10-3–(700±2.25)

0.998

The emissive response of H3sba ligand to NB was also measured, as shown in Figure 8. When the NB concentration is 1 ppm, H3sba shows no luminescence quenching effect. However, the emissions are quenched with quenching efficiency of 4.88±0.25, 3.97±0.17 and 11.27±1.07% for 1, 2 and 3, respectively. When the NB concentration is increased to 66 ppm, the quenching efficiency of H3sba is slowly increased to 3.49±1.04%, which is much lower than that of the three title CPs (28.74±0.89, 49.14±1.23 and 47.56±1.46% for 1, 2 and 3, respectively). These results suggest that H3sba is not available for NB sensing and the formation of CPs could facilitate efficient exciton migration from polymeric backbones to NB molecules to enhance sensitivity.40,41

Figure 8. Fluorescence intensity ratio (I/I0) histograms of compounds 1–3 and H3sba ligand. The emission spectra of H3sba (3 mg H3sba was dissolved in 3 mL ethanol) were measured at room temperature, excited at 333 nm. CONCLUSION Three luminescent CPs have been synthesized under the hydrothermal conditions. Compound 1 exhibits left- and right-handed helical chains. Compound 2 shows a 2-fold parallel


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interpenetration sql net with 44·62 topology. Compound 3 displays a supramolecular wave-like chain. The three title CPs are demonstrated to show highly selective and sensitive detection of NB in a wide linear detection range. The detection limits for NB are 0.33±0.02, 0.53±0.08 and (1.66±0.16)×10-3 ppm for 1, 2 and 3, respectively. Considering that more metal ions (such as Co2+, Ni2+, Cu2+, Zn2+) can be used in this synthetic strategy, the present study may enable the future development of much improved sensors for sensing of NB. ASSOCIATED CONTENT Supporting Information Detailed crystallographic data and structural refinement parameters, selected bond distances and angles, selected hydrogen bond parameters and additional figures for compounds 1–3, together with PXRD patterns, TG curves, IR spectra, figure of home-made device for detection of NB vapour and detailed luminescence data of 1–3 for detection of NB and other nitro compounds. This material is available free of charge via the Internet at http://pubs.acs.org. AUTHOR INFORMATION Corresponding Author *E-mail: [email protected]. Tel: +86 512-65880956. ACKNOWLEDGMENT This work is supported by Collaborative Innovation Center of Suzhou Nano Science and Technology, the National Basic Research Program of China (973 Program) (2012CB825803, 2013CB932702), the National Natural Science Foundation of China (51422207, 51132006, 21471106), the Specialized Research Fund for the Doctoral Program of Higher Education (20123201110018), a Suzhou Planning Project of Science and Technology (ZXG2012028), and


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a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). REFERENCES (1)

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For Table of Contents Use Only

Luminescent Coordination Polymers for Highly Sensitive Detection of Nitrobenzene Beibei Liu, Xiaoling Lin, Hao Li, Kaixuan Li, Hui Huang, Liang Bai, Hailiang Hu*, Yang Liu* and Zhenhui Kang

Three luminescent coordination polymers were used as excellent sensors for highly selective and sensitive detection of nitrobenzene.


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Three luminescent coordination polymers were used as excellent sensors for highly selective and sensitive detection of nitrobenzene. 29x25mm (300 x 300 DPI)


Luminescent Coordination Polymers for Highly Sensitive Detection of

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