Supporting Information

A naked-eye chemosensor for simultaneous detection of iron and copper ions and its copper complex for colorimetric/fluorescent sensing of cyanide

Gyeong Jin Park, Ga Rim You, Ye Won Choi, Cheal Kim*

Department of Fine Chemistry and Department of Interdisciplinary Bio IT Materials, Seoul

National University of Science and Technology, Seoul 139-743, Korea. Fax: +82-2-973-

9149; Tel: +82-2-970-6693; E-mail: chealkim@seoultech.ac.kr

Table S1. Examples for the detection of Fe3+ by organic chemosensors.

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Sensor Detection limit (µM) Percent of water in solution (%) Method of detection Reference

5 55 Colorimetric, Fluorescence [28]

0.19 99.9 Colorimetric [29]

56 90 Colorimetric [30]

19.5 100 Colorimetric, Fluorescence [31]

55.5 50 Colorimetric, Fluorescence [32]

13.5 50 Colorimetric This work

N

NH

O

N

N

OH

OHN

OH

SO3H NaO3S

NHOHN

N

O

NH

O N

HO

O

N N

OH

OH

HO

HO

OH

N N

HO

OH

N O N

N

O

S

N

H3CO

Table S2. Examples for the detection of Cu2+ by organic chemosensors.

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Sensor Detection limit (µM) Percent of water in solution (%) Method of detection Reference

18 60 Colorimetric [7]

29.5 60 Colorimetric [9]

2.1 99.9 Colorimetric [33]

0.9 99.9 Colorimetric [34]

2.4 70 Colorimetric [35]

2.9 50 Colorimetric This work

N

NH

O

N

N

OH

NNH

HO

O

O NO2

NNH

HO

O

O NO2

NN N

NHO

N

NN

S

HS

HO

N

CN

CN

NC

Table S3. Examples for the detection of CN- by organic chemosensors.

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Sensor Detection limit (µM) Percent of water in solution (%) Method of detection Reference

1.79 90 Fluorescence, Colorimetric [36]

5 99.5 Fluorescence [37]

19.09 99.9 Colorimetric [38]

2.4 70 Fluorescence, Colorimetric [39]

105 33.3 Colorimetric [40]

52.3 50 Fluorescence, Colorimetric This work

N N

N

NNH

NN

OH

N HHO

N

NH

O

N

N

OH

N

N

N

HO

N

N

OH

NO2

N

HO

NH

(a)

4

(b)

Figure S1. (a) UV-vis spectral changes of 1 (45 µM) after addition of 0-1 equiv of Fe(ClO4)2

in DMF/bis-tris buffer solution (1:1, v/v). Inset: Plot of the UV-vis absorbance at 475 nm as a function of Fe2+ concentration. (b) UV-vis spectral changes of 1 (45 µM) after addition of 0-1 equiv of Fe(NO3)3 in DMF/bis-tris buffer solution (1:1, v/v). Inset: Plot of the UV-vis absorbance at 475 nm as a function of Fe3+ concentration.

(a)

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(b)

Figure S2. (a) Benesi-Hildebrand plot (absorbance at 475 nm) of 1, assuming 1:1 stoichiometry for association between 1 and Fe2+. (b) Benesi-Hildebrand plot (absorbance at 475 nm) of 1, assuming 1:1 stoichiometry for association between 1 and Fe3+.

(a)

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(b)

Figure S3. (a) Detection limit of 1 (45 µM) for Fe2+ through change of absorption intensity at 475 nm. (b) Detection limit of 1 (45 µM) for Fe3+ through change of absorption intensity at 475 nm.

(a)

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(b)

Figure S4. (a) Absorption spectral changes of competitive selectivity of 1 (45 μM) toward

Fe3+ (1 equiv) in the presence of other metal ions (1 equiv). (b) The color changes of

competitive selectivity of 1 (45 μM) toward Fe3+ (1 equiv) in the presence of other metal ions

(1 equiv).

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Figure S5. Absorbance (at 550 nm) of 1 (45 μM) in the presence of Fe3+ (1 equiv) at different

pH values (2-11) in DMF/buffer solution (1:1, v/v, 10 mM bis-tris, pH 7.0).

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Figure S6. UV-vis spectral changes of 1 (45 µM) after addition of 0-1.2 equiv of Cu(NO3)2. Inset: Plot of the UV-vis absorbance at 437 nm as a function of Cu2+ concentration.

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Figure S7. Benesi-Hildebrand plot (absorbance at 450 nm) of 1, assuming 1:1 stoichiometry for association between 1 and Cu2+.

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Figure S8. Detection limit of 1 (45 µM) for Cu2+ through change of absorption intensity at 450 nm.

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Figure S9. Absorbance (at 450 nm) of 1 (45 μM) in the presence of Cu2+ (1 equiv) at different pH values (2-11) in DMF/buffer solution (1:1, v/v, 10 mM bis-tris, pH 7.0).

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(a)

(b)

Figure S10. The energy-minimized structures of (a) 1 and (b) 1-Cu2+ complex.

(a)

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(b)

Excited state 1 Wavelength (nm) Percent (%) Main character Oscillator strength

H → L + 1 333.26 65 ICT 0.0438

H → L 30

H - 1 → L + 4 2

Figure S11. (a) The theoretical excitation energies and the experimental UV-vis spectrum of

1. (b) The major electronic transition energies and molecular orbital contributions for 1 (H =

HOMO and L = LUMO).

(a)

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(b)

Excited state 1 Wavelength (nm) Percent (%) Main character Oscillator strength

H - 10 → L (β) 425.52 55 MLCT, π → π* 0.0276

H - 11 → L (β) 33

H - 15 → L (β) 2

Fig. 12 (a) The theoretical excitation energies and the experimental UV-vis spectrum of 1-

Cu2+. (b) The major electronic transition energies and molecular orbital contributions for 1-

Cu2+ (H = HOMO and L = LUMO / (β): β spin MO).

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Figure S13. Molecular orbital diagrams and excitation energies of 1 and 1-Cu2+.

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Figure S14. UV-vis spectra of 1 (45 μM), 1-Cu2+ complex (45 μM), and 1-Cu2+ complex with CN- (60 equiv).

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Figure S15. UV-vis spectral changes of 1-Cu2+ (45 µM) after addition of 0-60 equiv of TEACN. Inset: Plot of the UV-vis absorbance at 450 nm as a function of CN- concentration.

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Figure S16. Fluorescence spectra of 1 (45 μM), 1-Cu2+ complex (45 μM), and 1-Cu2+

complex with CN- (60 equiv) with an excitation of 350 nm.

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Figure S17. Fluorescence spectral changes of 1-Cu2+ (45 µM) with an excitation of 350 nm after addition of 0-60 equiv of TEACN. Inset: Plot of the fluorescence intensity at 395 nm as a function of CN- concentration.

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Figure S18. Job plot of 1-Cu2+ complex and CN- in DMF-buffer solution (1:1, v/v, 10 mM,

bis-tris, pH 7.0). The total concentrations of 1-Cu2+ complex and CN- were 200 µM.

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30 40 50 60

100

200

300

400

500

600

700

800

Intensity

[CN-]/[1-Cu2+]

Equation y = Ao +(Amax/2-Ao/2)*((1+x+22222/K)-sqrt((1+x+22222/K)^2-4*x))

Adj. R-Squar 0.98834Value Standard Erro

B Ao -2349.2800 2862.45137B Amax 1952.71813 826.55042B K 11012.6658 1619.23881

Figure S19. The association constant between 1-Cu2+ complex and CN- by a non-linear least-square analysis (fluorescence intensity at 395 nm).

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Figure S20. Detection limit of 1-Cu2+ (45 µM) for CN- through change of fluorescence intensity at 395 nm.

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